[Bullitt]

These people are afraid of what they don't understand, so they look to their most trusted source for answers. And when you are looking for evidence that agrees with what you think, regardless if it is correct or not, you're usually going to find it. You want something to be true so you find a way for it to be "true".
They believe this one thing, and are choosing to run their private organization that way. Nothing wrong with that. Of course they are incorrect about gays, but they are well within their rights to exclude them from leadership positions in their private organization.