I love this piece, and I think your main point is one that isn't made nearly enough.

Psychologically, sex is one of the most powerful forces in a human's life. That's why we remember some of our favorite sexual encounters in vivid detail, and why unpleasant or traumatic sexual experiences seem to scar our very being.

So... when you base an entire ideology around such a potent force, it's easy to see how anyone who follows said ideology is almost guaranteed to become a nutjob. Sex is too powerful to tame or control. Anyone who tries to do so, or tries to control the sexual expression of others, is willingly twisting their own psyche.