I highly recommend the HBO documentary "Believer." It shows the best and worst of Mormonism in one package. Dan Reynolds's idealism is familiar to me from all of the Mormons and ex-Mormons I know. I believe that idealism owes a lot to his Mormon background. That is the best of Mormonism.
But also on display in "Believer" is the willingness of Mormon Church leaders put what in their view is essential for the preservation of the institution and their own power—not an entirely distinct concept—ahead of the welfare of gay members of the Mormon Church.
The Mormon Church has a doctrinal view that is very negative about gay marriage. But the harshness of its policy against gay marriage goes well beyond even the harshness of its anti-gay-marriage doctrine. (See my post "The Mormon Church Decides to Treat Gay Marriage as Rebellion on a Par with Polygamy.")
Coming from a Mormon background, my own views about homosexuality and gay marriage evolved over time. If you had talked to me back in 1990, you would not have heard the most enlightened views about homosexuality. But over time, I have come to value "diversity" more and more—not as the codeword it often is, but in a genuine appreciation of what we can all learn from and gain from human beings who are different from us. Indeed, love across chasms of difference is, I believe, the key to making a place for God in our world. And love across chasms of difference soon reduces chasms of difference to the size of cracks in the sidewalk.