I believe to some extent that is true. Personally I feel I continued to attend meetings and preaching to make myself not think about the reality that what I was doing may not be true. Almost like I had to continue to prove to myself that its true. But It was easy for me to eventually give it up as not being true and stop doing those things because I had no family or friends in the religion. I only attented for 5 years and I knew of life outside of JWs.
For someone who only knows that way of life or has all their family and friends in it and has been doing it for years, then yes I think they would continue to do it for reasons like peer pressure or for reasons that they know no other life, just like an animal who is trapped in a cage and knows nothing else. If the person has some doubts but feel they are stuck, then continueing to preach and attend meetings may be a means of justifying those doubts. Someone in that situation could have guilt if they left and guilt can be a powerful tool to motivate someone to do or not to do something.
Every person is different, every situation is different.