And in other churches.
It's happening because in the 21st century, homosexuality trumps religion, morality, common sense, safety and God.
In the short run, anyway.
In the long run, they are all damned.
That's just a manifestation of a bigger problem. I mean, abortion also trumps religion, morality, common sense, safety, and God, and don't forget the U.S. Constitution, too. Ditto for euthanasia, where we're headed.
So what's the common denominator? Hedonism and individualism ("my body, my choice"), in contrast to Christian humility ("you have been purchased, and at a price"). Our society has turned from God, and our churches and our attitudes are sufficiently enmeshed in that society that it's tough to keep from turning with it.
That's the long answer. The short answer is that the world and the devil are stronger than they've been in a long time, and the flesh ain't no slouch, either.