None of which is surprising. But it does not in any way demonstrate that the Mormon beliefs are wrong. Not liking something does not mean it is untrue.It was a fascinating account with many interviews of Native Americans' experiences with being told by the LDS church they were descended from the Lamanites. They included believers and non-believers but the main points of evidence were, there is no archeological evidence of any battles with shields and swords, the Mormon version of these peoples is closer to European than Native American peoples, again, no evidence. And all the DNA studies show Native Americans are descended from Asian peoples not from Israelites.
They also noted it was not in any indigenous people's traditions in any of the Americas to completely wipe out any tribe they went to war with so the idea they would have obliterated the Nephites was also not consistent with any evidence.
The people interviewed who were not converted to Mormonism were insulted by the claim their dark skin was from sins and they'd turn white when God forgives them or whatever the myth is. And they were perfectly happy with their own beliefs and traditions.
Christian teaching is that we are all sinners and need to believe something or other to be saved. The Mormon idea of being punished by being made black and being rewarded by whiteness when god forgives you is not very different.
They are both wrong, though.