to play devil's advocate on your own question:

I guess the other thing is, if I was LGBTQI and wanted to get married to my partner, why would I go to a church? Why would I want to support an institution that is openly hostile to my nature?

to answer this one- some LGBTQI peeps identify as christian and are an active part of the church. that the church largely excludes them doesn't stop their belief or desire to belong. a complicated tale. and for anyone reading, the bible, while openly decrying "sodomy" is not strictly against lesbians or gays.