The same-sex movement didn't wait around for theologians to develop a new Christian anthropology that took their experience into consideration. They moved on and left it to the churches to decide if they wanted to follow.  For better or for worse, most believers take their cues from culture, not church, and certainly not from theology. The culture now tells us that human nature, if there is such a thing, is more expansive and varied than we ever thought. 

The challenge to the churches is to respond in ways that are faithful to both Christ and Culture (to borrow Niebuhr's terms). The challenge to the LGBT community is to articulate their reasons to believe within a community that can't figure out what to do with them. I'm not sure the twain will ever meet.