My short answer is Mesomania, as I discuss on that blog, here.
Despite widespread Mesomania, I think most members of the Church (LDS) believe the Hill Cumorah is in New York. When they discover that LDS scholars and educators actually think the Hill Cumorah is in Mexico, they are surprised, if not shocked.
In a highly regarded book on the Mesoamerican theory, a prominent LDS scholar and BYU faculty member wrote: “There remain Latter-day Saints who insist that the final destruction of the Nephites took place in New York, but any such idea is manifestly absurd."
Knowing that most members would reject this condescending statement, LDS scholars and educators don't emphasize this fundamental aspect of the Mesoamerican theory. Instead, they emphasize the authority of their expertise and expect people to accept their theories on that basis alone.
[As always, I emphasize that my discussion here focuses on LDS scholars and educators who promote the Mesoamerican theory, whether they are doing so intentionally and knowingly or simply by default (because it's what they were taught). There are plenty of LDS scholars and educators from many disciplines who don't accept that theory, but it's impractical to write "LDS scholars and educators who promote the Mesoamerican theory" every time I refer to this group. I also refrain from identifying anyone by name because none of this is personal, and because people change their views anyway. Eventually, of course, I hope all LDS scholars and educators will unite around the New York Cumorah, but until that happens, we need to continue discussing what is happening in the real world and how to address the problems that naturally result from the two-Cumorahs theory.]
People think that messages are persuasive when they are factually correct, but psychology and actual experience show that is not always, or even usually, the case. At the extreme, absurd messages are not widely accepted, but correct messages are often ignored or even disbelieved.
The reason: there are other aspects of any message that can be more influential or persuasive than the merit of the message itself.
This concept has been summarized by three elements of influence or persuasion:
The merit is the message.
The medium is the message.
The messenger is the message.
The merit of a message includes the quality, reliability, credibility and relevance of the evidence as well as the soundness of the reasoning and arguments. These can be compared and contrasted, but ultimately a decision about the merits is subjective for each individual. Experts can tell people what to think, but they can't force people to agree with them.
In my view, of course, the merits of the various theories strongly favor the North American setting on every front, but the merits are not the most persuasive element when it comes to Book of Mormon geography.
Because the merit of a message is subjective, people consider the other elements.
The medium of a message is the channel through which it is communicated to people. In the case of Book of Mormon geography, we have an oligarchy of channels produced by what I have referred to as the citation cartel. Another term for it is groupthink. The channels consist of books, articles, blogs, and other web-based communications (Facebook, youtube, etc.) that are dominated by scholars, educators, and authors who promote the Mesoamerican theory. Because many of these channels are closely affiliated with BYU (e.g., most authors are BYU faculty or current or former students), there is an inference of official Church sanction or support. The inference is corroborated by officially approved artwork on lds.org that appears in manuals and on the walls of chapels and temples.
The fascinating thing about the medium is the implied sanction or support is actually a false implication, because officially, the Church takes no position on anything other than Cumorah, and has even hedged on its prior position on Cumorah.
Because the medium is, or should be, ambiguous despite its uniformity, people consider the final element: the messenger.
The messenger of a message can have the deepest impact of all. It has been said* that "When a legitimate expert on a topic speaks, people are usually persuaded. Indeed, sometimes information becomes persuasive only because an authority is its source. This is especially true when the recipient is uncertain of what to do."
Scientists have shown by analyzing brain activity that people who receive expert advice follow that advice without even thinking about the merits of the message. The messenger becomes the most important factor.
In the context of the Book of Mormon, one might think LDS prophets and apostles would be the most persuasive authority, but that's not the case. LDS scholars have successfully supplanted the prophets and apostles by questioning their reliability and credibility on the issue of Cumorah.
This is exactly what we expect, because when it comes to persuasion, it is not someone who is in authority who is most persuasive, but someone who is an authority. Most people prefer expertise over hierarchy.
Think about this. Which is more persuasive on the question of the Hill Cumorah? A "general" authority or a "specific" authority (meaning a PhD)?
Evidently, the specific authorities--the LDS scholars and educators--have become more persuasive than the general authorities--the prophets and apostles who have spoken on the issue.
With this in mind, let's assess the credibility of the messengers.
An authority is credible because of the combination of expertise and trustworthiness.
(In the case of Joseph Smith and Oliver Cowdery, no mortal was more expert than these two in terms of interacting with divine messengers (including the Lord Himself) and in terms of handling ancient artifacts, including not only the plates they translated but the plates in the repository in Cumorah. Both were highly valued for their trustworthiness as well because they related their shared personal experiences as clearly as words can be. Their detractors dispute both their expertise and their trustworthiness, but only because of disbelief; there is no actual evidence to support the arguments of the detractors.)
Expertise. We can stipulate to the expertise of the LDS scholars and educators, all of whom presumably have at least a college degree and a certain level of relevant training and experience. Among them are PhD archaeologists, anthropologists, linguists, etc. Some are lawyers, historians, or scientists.
Their academic qualifications are the primary persuasive tools used by the Mesoamerican advocates. They have PhDs, and they teach, or have taught, at BYU. On that basis alone, they expect LDS people to accept their theories.
Of course, it's a serious mistake to automatically assume that one's training makes one an expert, particularly where there are no degrees, let alone advanced degrees, in Book of Mormon studies. All we can reasonably assume is that the LDS scholars and educators have enough expertise to effectively communicate their conclusions; i.e., that they are competent enough to not be misunderstood.
Trustworthiness. To deserve deference, the messenger must be trustworthy. As recipients of the message, "we want to trust that a communicator is presenting information in an honest and impartial fashion--that is, attempting to depict reality accurately rather than to serve self-interest."**
It is here that the Mesoamerican advocates fail, but the recipients of their message, by and large, don't realize it because the scholars and educators have monopolized the medium of the message.
Through blogs and books, I've shown that every argument made by the Mesoamerican advocates regarding Cumorah is deeply flawed on the facts. I think the scholars and educators realize this, which is why they've suppressed Letter VII and the teachings of the prophets and apostles about Cumorah. They simply ignore them in their work, which means they are also ignored in Church manuals and media (since the departments that prepare those materials are staffed by former students of the LDS scholars and educators who promote the Mesoamerican theory exclusively).
Furthermore, the citation cartel refuses to publish articles that challenge their Mesoamerican theories and their hegemonistic position in LDS culture.
In my view, it is this refusal to present information in an honest and impartial fashion that deprives LDS scholars and educators of the legitimacy they have unduly seized in LDS culture.
Working backward, if the messenger is the message, then the Mesoamerican message should not be believed because the messengers of that message have not been trustworthy; i.e., they have consistently refused to present information "in an honest and impartial fashion."
If the medium is the message, then the Mesoamerican message should not be believed because the medium consists of a oligarchy of groupthink, which I call the citation cartel.
If the merit is the message, the Mesoamerican message should not be believed because the facts and reasoning used don't hold up to scrutiny.
The obvious remedy (short of intervention by senior Church authorities) is to have a forum that allows messages to be presented "in an honest and impartial fashion."
The citation cartel has had decades to facilitate this, but they have steadfastly refused to do so. Perhaps a third party can intervene to provide such a forum, but LDS scholars and educators have already rendered themselves untrustworthy as messengers. We can expect that whatever they might present will be a continuation of their motive to serve their self-interest instead of a desire to depict reality accurately. At least, that's a factor that should be considered in the process.
There is also the problem of inertia; i.e., the messengers have not been trustworthy, so the media they have dominated is equally untrustworthy. An honest and impartial forum would have to somehow undo the decades of influence from the citation cartel media. That's possible, but would require focus and commitment on the part of the very people who established the citation cartel to begin with.
Finally, the merit of the message cannot be determined by the LDS scholars and educators as it has been in the past. Once finally presented in an honest and impartial forum, it must be left to each individual Latter-day Saint to decide which message has the most merit.
(My response to their approach is as much disclosure as possible. I think the more information people have on this topic, the less they are persuaded by the Mesoamerican theory, despite the appeals to authority by LDS scholars and educators and the domination of the media by the citation cartel. In other words, the merits will prevail when people are given honest and impartial information. As a start, I've offered a comparison chart for Book of Mormon geography here. I've tried to be honest and impartial and accurate. I've sought input from Mesoamerican scholars and educators. None has been offered, which suggests the chart represents both sides reasonably well. Suggestions for improvement are always welcome.)
*Presuasion, kindle, location 2540.
** Ibid, location 2556. Some ask what possible self-interest LDS scholars could have in perpetuating a theory of geography that repudiates the prophets and apostles. Each individual has his/her own set of motivators, but at the risk of overgeneralizing, people fundamentally want to do the right thing. Remember, Mesomania did not originate with any current LDS scholars and educators. It was developed in the 1920s and imprinted on all of us at an early age. LDS scholars and educators have relied on 1) the historical mistake from the 1842 Times and Seasons and 2) a misreading of the text that conflates the narrow neck, the narrow neck of land, and the small neck and assumes this feature is in Central America. Consequently, they have spent decades and entire careers promoting the Mesoamerican theory. They are understandably reluctant to reverse course, having taught thousands and influenced millions of members of the Church. And, in fact, due to Mesomania, many of them can't unsee Mesoamerica; their interpretations have become the text in their minds. It's not a matter of assigning blame; none of these scholars and educators has bad intentions. We just have to work through the issue by reaffirming faith in the prophets and apostles to reach agreement on the New York Cumorah, and then working, step-by-step, through the evidence and the text.