There is not a single religious group in the world which does not have its share of "imbalanced" individuals who are attracted to such groups precisely because they can serve as a "cover" for their "over the edge" thoughts and behavior patterns which would otherwise stand out like a sore thumb in the overall "normal" population.
There are no exceptions.
And it's been this way since the first day on Earth.
Anyone who believes that a particular religious order is comprised of all "holy men" and "holy women" living lives of devout purity, selflessness, and sanctification, is unbelievably naive and needs to get out more.
I am not criticizing religious orders and followings as such; only pointing out the obvious fact that there's no shortage of nutjobs and others who follow and join all religious groups for all the wrong reasons.
Unholiness is always attracted to holiness.
Nor is it a secret that people born and raised within these groups, often to the third generation or more, know nothing of the world outside their small social circle, take their memberships and teachings 'for granted', do not see themselves as individuals who have repented and 'returned', and can frequently be tempted to stray from the fold just to "see what it is they've been missing".
It happens inside every faith community and just because it happens does not discredit the teachings and faith of the group itself - it's just the human condition showing itself.