My guess is tribalism and self-hatred.  

How often do we see some of the most spiteful and vociferous of the anti-gay politicians and religious figures are revealed as homosexual or pedophiles when they think no one is looking?
George Rekers
Ted Haggard
Glen Murphy Jr.
Bruce Barclay
David Dreier
Larry Craig
Ed Schrock
Phillip Hinkle

All vehemently anti-gay and outed through their own private actions.