In previous threads, we discussed the possibility that there are more INTJ ex-jws than in the general population because we question everything.
INTJs are also the least likely to believe in god, which makes it hard to stay in a religious cult. In my case questioning the existence of god was easier than questioning the watchtower. Though I think the prevalence of INTJ on forums is more about the style of communication that we prefer - the wrongs of the cult are both numerous and varied enough to offend any personality.