IME, it is the bigot's own fear – fear of anyone different, fear of their own unexamined sexuality. They never questioned or explored – they just fell into what they live. And, they fear anyone so self-actualized as to know something different in themselves from the "norm" the world tries to impose. Bigots aren't into self-introspection. They need the world to be simple: this is right and good and is the only way vs. that is wrong and must necessarily be evil and thus be opposed at all costs.

The religiosity or political or cultural animous are all just skins bigots cloak themselves in to give their poisonous fears a corrupted veneer of legitimacy.