Instead of confusing students (and everyone else) by insisting that Joseph and Oliver were wrong, our scholars would teach that Joseph and Oliver were honest, reliable, and credible.
Instead of the chaos arising from people advocating their own ideas about the location of Cumorah, everyone could unite behind the prophets.
Instead of blithely pretending historicity doesn't matter, we would all see how "proof of its divine authenticity" (to use Joseph's words) serves to reinforce the convincing power of the Book of Mormon.
Such unity and understanding would reinvigorate efforts to share the Book of Mormon with the world.
What impedes this progress?
Despite the effort to "de-correlate" the New York Cumorah by removing it from Church history,* everyone can read those teachings. Even the most adamant M2Cers such as FAIRLDS and Book of Mormon Central reluctantly acknowledge that the prophets have taught that Cumorah is in New York.
Why do they fight these teachings?
The M2Cers invoke four main reasons.
1. Conflation of teachings. Throughout Church history, there has been a clear distinction between the fact of the New York Cumorah and various opinions/speculation about the location of other events. A key point: the location of Cumorah doesn't determine the location of other events. There are hundreds of potential sites for Book of Mormon events, and untold possibilities have been long lost to history. Yet modern LDS scholars conflate the two separate topics to confuse people into thinking the fact of Cumorah was mere speculation. That's outcome-driven revisionist history that everyone can see.
2. "No evidence." M2Cers insist that the prophets were wrong about Cumorah because there is "no evidence" in New York. But that's a misreading of both the evidence and what the Book of Mormon itself says.
It's true that there is "no evidence" in western New York of the type of society the M2Cers have dreamed up to fit their Mesoamerican theory. But there is also "no evidence" in the Book of Mormon itself for such a society. The text never refers to massive stone pyramids, volcanoes or the three Js of Mesoamerica: jaguars, jade, and jungles.
It reality, there is plenty of extrinsic evidence in western New York, but it's not what the M2Cers seek. If people accepted the teachings of the prophets, they would interpret the text accordingly.
The extrinsic evidence (archaeology, anthropology, geology, geography) corroborates what Moroni said when he told Joseph that the abridged record was "written and deposited not far from" Joseph's home near Palmyra. The evidence corroborates the actual descriptions in the text, and such evidence should inform our interpretation of the text.
3. "Doesn't fit." M2Cers insist that the prophets were wrong about Cumorah because western New York doesn't fit their interpretation of the geography-related passages in the text. But insisting on only one possible interpretation of the text violates a fundamental principle of textual interpretation.
Anyone who reads the Book of Mormon can see that the passages describing geography are relatively vague. The vagueness of the term "land northward" is compounded by the question whether it is a proper noun or a relative term. In Utah, Salt Lake City is both the land northward and the land southward, depending on whether the reference is Provo or Ogden.
The terms "narrow neck," "small neck," and "narrow neck of land" could refer to the same geographical feature or to different features. The term "head of the river" could refer to the source or a confluence. Common English usage circa early 1800s finds examples of multiple meanings for these and other terms.
4. Heartlanders are nationalists. Lately some M2Cers have resorted to a straw man fallacy to deter the Latter-day Saints from learning about the teachings of the prophets regarding Cumorah. They claim that people who accept the New York Cumorah are American nationalists. In reality, Latter-day Saints who still believe the teachings of the prophets have a variety of view about other Book of Mormon settings. Many Latter-day Saints who accept the New York Cumorah don't live in the U.S. and couldn't care less about American politics.
The question boils down to whether we accept or repudiate the teachings of the prophets about the New York Cumorah.
We've discussed all of this before. Some LDS are far better informed than others about all of this.
* The "de-correlation" of Cumorah is evident not only in the efforts of FAIRLDS, Book of Mormon Central and the Interpreter, but also in Saints, Vol. 1, the editorial content of the Joseph Smith Papers, Opening the Heavens, the BYU and CES fantasy maps, and pretty much every recent commentary on the Book of Mormon and most artwork. Despite all of this, the teachings of the prophets remain part of the historical record.