Great thread and comments!
I genuinely think most jws believe 100% in the faith, but those that do have doubts, or see the facts for what they are, think that they are personally at fault.
Just like the fable of the "emperors new clothes" (google it if you have not heard of it), no one who sees the reality is confident to actually speak up! With everyone and everything around them constantly ooohing and ahhhing about the "truth", very few will dissent.