It may be that the Mormons do a great amount of good. But it may also be that they do some bad. And it is matter of record that they are a politically active organization. The problem with dogma is that people will support a motion (surpression of gay rights, women's rights, etc) not based on its merits, but based on its alignment with the system.
The problem is, how do you tell the good from the bad? If you are a Mormon, good is whatever aligns with your dogma. Otherwise, good is whatever causes no unnecessary harm, which is a more difficult question to answer. Over time, these two will diverge as culture evolves and dogma remains. For the believers, facts that conflict with their antiquated view will simply be ignored.
The modern story of the translation of the Book Of Mormon from gold plates as portrayed in church media is one of Joseph reading the gold plates while he or an assistant transcribes them, but this conflicts with the church's own historical record. It is an attempt to cast an antiquated dogma in a light acceptable to modern culture.
"Saints' Herald" is an official church publication, like the modern "Ensign" magazine. In October 1879 it printed the "Last Testimony of Sister Emma" (Joseph's wife). I found it quoted by "Religion and Sexuality: The Shakers, the Mormons, and the Oneida Community".
In writing for your father I frequently wrote day after day, often sitting at the table close by him, he sitting with his face buried in his hat, with the [seer] stone in it, and dictating hour after hour. ... The plates lay on the table without any attempt at concealment.
That's right. He stuck his head in his hat and looked into a magic stone and the words materialized before his eyes. Magic stones, like talking snakes aren't very common in the 21st centurary. There is no place for them, just as there is no place for the surpression of gay rights, the supression of women's rights, and a policy of expansion. The bad done by an organization is not excused by the good.