I only know 3 JW's and they all seem to lack self esteem. Two of them were not born into the faith and at the time of their recruitment they both were going through some stressful family issues. The hope of living in a problem free Paradise on Earth makes their present situations tolerable.
Based on the 3 I know personally, my view is that they are very nice, sincere and honest people. One of the 3 is a friend of mine and I would do anything I could to help him in time of need. They believe the "truth" is the truth and feel they are doing the right thing by prosyletizing.