I think there are three types of people that go to the meetings.
The ones who were brought up in it who just view it as the faith they were brought up with and go out of tradition and accept what they are taught.
The ones who enjoy the power thing, who may know a lot of stuff that is skew, but could never give up their position as an outstanding member of the congregation.
The ones who are sincere whether brought up as a J dub or those who sincerely studied and became one but are plagued wth doubts about many things. Many of these are for what ever reason are still attending, and others who eventually decide enough is enough and stop attending.
I would have to say that probably, it is the case that the more you read paticularly the older publcations can have an affect on you . I always remember reading an older book. I think it was "let your Kingdom come" which went into the explanation of the king of the north and king of the south. I sincerely wanted to understand the prophecy on this. I read the book about 3/4 of the way through and thought this is pure nonsense. But put it down to Jehovah shedding new light in newer publications etc. So yes after a while , like a slow jigsaw puzzle. you start piecing many of these doubts together and remember them when you eventually come to the conclusion that there is something seriously not right here.