I think it might go deeper than religiously-induced abhorrence of one’s sexuality. I suggest the primary ‘motor’ is that the homophobes sit on a lake, if not a sea, of unacknowledged misogyny as I wrote some eight years ago, with a secondary factor probably being equally unacknowledged father-hunger and confusing such hunger with same-sex attraction. Here’s a link to the post I wrote.
http://nopartyline.blogspot.com/2012/05/through-nasty-witches-brew.html