There is a clear distinction between the teachings of the prophets on two topics:
(i) they have consistently, specifically, and persistently taught that the hill Cumorah (Mormon 6:6) is in western New York.
(ii) they have consistently, specifically, and persistently taught that the rest of the Book of Mormon geography has not yet been settled.
How do the M2C proponents get around this obvious problem for their theory?
They cause confusion by conflating the two separate issues. That is, they cite the teachings of the prophets about the uncertainty of the rest of Book of Mormon geography and claim those teachings also apply to the Hill Cumorah.
It’s easy to see through this subterfuge, but so many people want to believe M2C–they want their M2C bias to be confirmed–that they eagerly accept the confusion.
FairMormon is one of the best at using this tactic effectively to confuse members and Church leaders. You can search this blog for “FairMormon” and see lots of examples.
Because of the confusion caused by M2C, you will often hear such arguments as this: “Mesoamerica, North America, Chile, Baja–they all have their pros and cons, but the prophets have never been specific, so the geography doesn’t matter.”
Of course, it’s not true that the prophets have not been specific about Cumorah.
You can cite Letter VII and all the other specific, prophetic teachings about the New York Cumorah to M2C proponents, but it won’t make any difference. They are convinced that the prophets have left it up to the intellectuals–meaning, themselves and the entire M2C citation cartel of FairMormon, BOMC, BYU Studies, etc.–to solve the question of geography.
They will continue to confirm their bias regardless of what the prophets say.
Source: Book of Mormon Wars