Awesome comments so far, and I must say I agree with them all. For me personally it is this:
The double standard of what they say and the reality. They say "Do your best. Just do what you can do. Jehovah knows your limitations. Be modest (recognize your own limitations)" But the reality is at every single meeting and in every single article you get bombarded with "DO MORE. Reach out! Extend yourself." etc.... So the result is, even though you ARE doing all that you can possibly do, you feel worthless and guilty.
I've come to realize this is nothing more than a mind control trick. If you feel miserable about yourself you will be too down to question anything, and that's exactly where they want to keep you.
I spent a large number of the years of my life as a true believer. I was 100% from 18 to about 37, believed it all and felt miserable and guilty and depressed over my own very minor shortcomings. All for what? Nothing. For a bs lie.
Since I've woken up I am no longer guilty, no longer depressed and I'm actually LIVING my life. To me this is one of the largest travesties they inflict upon their members because it affects each and every one regardless.
Who was it that said "Religion is a snare and a racket!" ? CT Russell or Rutherford? One of them said that and they couldn't have been more right.