Who cares about the geography of the Book of Mormon? Does it have a salvific or applicable value? No, from an eternal perspective, Book of Mormon geography is completely irrelevant. The Book of Mormon exists to bring people to Christ, so that they might repent of their sins and follow Him into the waters of baptism. That's it. Nevertheless, some people really like the Book of Mormon and want to know more about it and the people who wrote it. That's where geography comes in.
Just as knowing about the Roman empire and first century Judaism can inform our readings of the New Testament, just as ancient near eastern geography and and a knowledge of Canaanite and Babylonian religious texts can inform our readings of the Old Testament and just as 19th century American history and geography can enrich our readings of the Doctrine and Covenants, having a credible geography of the Book of Mormon lands can give us richer readings of the text for with such knowledge we can lean on the religious writings and practices of neighboring or participating cultures. As someone once said, "a text without a context is a pretext". Besides, if the Book of Mormon has any historical value then it had to have happened somewhere, right?
I personally believe that John L. Sorenson has figured out the correct general paradigm for where in the Americas the Book of Mormon events happened, Veracruz, Chiapas and Guatemala. I believe this is the case because as I read the BoM with that scheme in mind and compare the text to what we think we know from archaeology, for the proper time and place, the text makes more sense to me; there are productive convergences in the movements of people in time and space. A Mexican setting for the Book of Mormon also makes certain prophecies make more sense.
The Lord has said that in the latter days "the Lamanites shall blossom as the rose"(D&C 49:24); Mormons currently have 13 temples in Mexico and 6 temples in Central America, Certain prophecies in the Book of Mormon(3 Nephi 20:16; 3 Nephi 21:12) also make a lot of more sense when viewed in light of Mexican and Central American migration trends in the US. However, I don't see similar things happening for the Iroquois or Seminoles.