Starting with a quote:
on the other hand, if you are a mormon who believes that the BoM captures a genuine revolution the priors change. if you presuppose the the genuine core of mormon belief one could construct a scenario where such a contact could occur so that the extant remains would be difficult to discern. . . so depending on the parameters you can make a plausible case in the light of your priors.
I think this needs to be stated more than once. The answer to why Mormons believe as they do can be traced to what Tim Bulter said, "When I read the Book of Mormon, I feel a palpable glow. I believe it's the word of God." This is a unsophisticated description of the spiritual witness, but a good example of the Mormon priority of religious understanding over apologetics. For Mormons, their experience with God is the ultimate proof they have of Mormon claims. It is a personal and not an academic exercise. To quote Richard L. Bushman, the current go to person:
Mormonism has always been an embarrassment to Christianity. It goes back to the 1830s when, on their own left, Christians had to face the Deists, who said the Christian miracles were ridiculous. To defend themselves, Christians had to find some kind of rational support. William Paley, of course, is the archetypical character, but there were scores of books written trying to mobilize evidence that you could believe the resurrection, that those witnesses were authentic.
While they were fighting that battle, the Mormons on the right came up with these ridiculous stories of angels and gold plates and claimed the same right to believe in miracles, mobilizing the same kind of evidence that Christians used for the resurrection. This required Christians to repel Mormons to prevent the Deists from grouping them with the lunatic fringe.
Christian groups have been as forceful as any in trying to put down the Mormons, I think, partly to protect their position as respectable philosophically. I once in a meeting asked a group of evangelical Christians – a small group; Mark Noll was there, Richard Mouw, various other distinguished people – why don't we join forces in making a case that there are grounds for believing in the existence of God simply because the spiritual life confirms it? People believe there is a God because it's manifest to them spiritually.
They really didn't want any of that. They wanted to maintain their philosophical, rational claims, defending their miracles on sort of a quasi-scientific basis. They did not want to get in bed with the Mormons and their strictly subjective view of things. So there is kind of a gap intellectually. Mormonism has never embraced philosophy; it is not particularly interested in philosophy. I would say our most natural ally among the philosophers, frankly, is William James whose view of God is very close to the Mormon view of God. . . Because the emphasis is on experience and belief in a God.
This isn't to say there isn't any "comprehensive defense/explanation" of Mormonism. There is a surprising amount of such if you will actually take the time to look. And these are not just from amateur (although there is that) writers trying to be persuasive, but Phd's in fields from Law to Anthropology. Almost none of the articles they write will ever be in peer reviewed journals, but that is the nature of any religious apologist work. What is sad is that there is such a large volume of relatively good quality apologia that is virtually ignored. Even those who should engage it don't as if it doesn't exist.
And here is where Ross Douthat and others miss the boat entirely. They seem to argue against Mormonism without having at least a cursory understanding of Mormonism and its contemporary defenders. What is amazing is all this talk about Mormons as "literalists" is only partly true.
Unlike the most hardened Bible believers, Mormon theology about Prophets, Scriptures, History, and etc. is extremly flexable and nuanced. For instance, the whole talk above about how "The Pearl of Great Price" doesn't match with the current "Book of the Dead" we clearly have is not very troubling to Mormons who understand their own theology. It brings uncomfortable questions, but ultimately doesn't put "The Pearl of Great Price" into question so much as the process and meaning of Revelation itself. Too many people (even LDS members themselves) try to shoehorn Mormonism into the same category as Scriptural Inerrantists, when that is actually not the case. This is one example of too many where outside perceptions of the way Mormons think and believe are thrust upon them out of caricature rather than reality.
That is the real tragedy here. Arguments against Mormonism from the Right and the Left have been, from the point of view of Mormons, mostly strawmen bolstered by centuries of tradition that Mormons half-heartedly care about participating in because of fashion.