I think the literature is written as they are programmed to think. It is a survival mechanism designed to thwart anyone from leaving, and maintaining loyalty to the organization. (Just like any similar group).
It is far more pallatable for one to feel a sense of moral superiority to adopt the thinking that "I will be humble and wait, for that is the best way, blah blah." Rather than be "rebellious" and investigate and think independently which they have been chided to abhor.
Clinging to the beliefs from the FDS, and the WT is a way for emotionally weak people to not have to think, to not have to make hard decisions. The way you are supposed to believe and live is already defined for you. How freaking convenient. And it is the truth, and right, by golly this is freaking fabulous! It alleviates any insecurities.
I used to think to myself when I was a little girl, that I was so lucky, I mean how could I be so lucky to be born into the right religion and all of these other people are going to die, or learn the hard way. I knew why things were the way they were. It was the golden ticket.
I know better now. :)