You will get as many answers as there are people. Depends on one's conditioning and one's story. What's your story?
I find most homophobia generally has its roots in dogmatic religious fundamentalism. "Gawd said we can hate them there peoples so thats just what were a gonna do." Of course in this case, the little god is nothing more than a projection of one's ego and not the all encompassing nature of GOD (Universe, all that is, etc). God hates noone. Not even bigots! People tend to project outwatrds what is contained within them.
The autorocities commited in the name of the little egoic god are numerous indeed but as deeper awareness comes these "sins" are washed away.