Great OP!
So very true. "Cults" cannot be understood without understanding our own psychology, and without understanding the broader social sphere of influence any social environment can have on an individual. "Cults" do not exist in a vacuum, but rather have a role in our social environment, contributing to the "needs" of some individuals, no matter how flawed, dysfunctional, and extreme they are.
Fear, cognitive dissonance, and the much quicker to respond, "intuitive", (as opposed to rational), mind, play a significant role as to why cults exist, how they operate, and how they are successful with keeping their subjects under their control.
d4g