This reply is based on personal experience only and represents my opinions based on said experiences.
On a whole (heh heh) yes… can a “normal” girl be just as good? Yes. But, it doesn’t seem to happen often. I agree the uninhibited view is a factor but the common denominator I have found is their communications skills in letting you know what they want you to start/stop doing.
Also, I think the male “hunter” is a factor… searching for a no strings, primal experience, once he bags a crazy-- who as I said has a better chance of blowing his mind, he now has a “profile” of the type girl that matches his needs.
When the urge hits again, does he go to a church social to meet a quiet bookworm? No, why change a successful formula. This would also be a cause that supports my “if you have had a crazy, chances are good you have had a couple or more”.
Last thought. are they worthwhile? NO… no matter what resist the temptation for even one more encounter. That “one more time only” can upset the apple cart—phone numbers, last names etc. They are called “crazy” for a reason and they love drama, being victims, are impulsive and you will just piece of the puzzle.
Move on to the next and if your ready to settle down, try the next church social.