My reasons for leaving were 2 fold. I stopped going to meetings because I suddenly realized that I had gone from the happiest I'd ever been in my life to the most miserable, and I needed time to think about that. I still thought that I might return at some point in the future. I even prayed about it.
I then stayed away because I began examining the doctrines and the literature more closely. The doctrines seemed untrue (or at least doubtful and unsupported) and the literature seemed poorly researched (or even intentionally misleading). So that settled it for me. I wasn't going back and I felt pretty good about it.
All That started me thinking about all religions along these lines, and soon, I began to see myself as an agnostic. Later, an atheist, though the only thing that changed was my definition of the word.
Like you, Nico, I don't think we threw out the baby with the bath water. I tend to feel take that as an insult, or a convenient attempt by believers to psychologize atheists. I try not to do that back at believers, though I'll fall into that trap more easily with JWs.
I almost agree with you and the person you were quoting on how beliefs are formed. I wouldn't say that you have no control. People ignore evidence or solid arguments that oppose beliefs they favor. Especially if they have invested a lot in those beliefs. They could try to listen to those points more openly. But that only offers them a very limited amount of control. I would still say that -- IMO -- you're both mostly right about that. :-)