I think another big problem is that when someone starts a study, they are told (Through literature lol) that there is this eternally binding "spirit of love" in the christian congregation of JW's, and then they're told that the world will try to draw them away. I don't know about everyone else, but I am a naturally curious person. So if I'm told that there's something really cool that only a few people around the world can have, and I'm special and can have it but others will try to keep it from me, I will make EVERY EFFORT to try and keep that special something. That is the primary draw of the WTS.
Let's say after a while they feel nagging doubts so they look online to research it. BAM "WTS is a cult! It's evil! Stay away!" but no that can't be correct, the elders and members are so nice... maybe the internet is controlled by Satan and... yes that must be it! Satan wants me to lose my faith! Well heck, those disfellowshipped people don't know what they're talking about, the apostates! I'll just ignore them and go back to being happy. This is what most people will think upon recieving nagging doubts.
Once conditioned, it's hard to get out of it. Let's say a person wants to know if the WTS has ever made false prophecies. How do they go about finding out? Well, they ask an elder. But let's face it, true or not true, the elder won't admit to it. So after asking him, they go online to research it. But eh, well, all the people going against the society online are "apostates" and therefore controlled by Satan. Therefore they must be biased on the opposite side of the fence.
Well, now we face a serious dilemma. Who is telling the truth? Obviously we must find a middle party who is NOT biased. Sounds easy right? WRONG. People on the right wing have spent a lot of time defending their religion, and know how to do it very well. People on the left however, have done a lot of their own research and also present very convincing arguments! WHO IS RIGHT? Well guess what? For religion there really is no middle ground! Either you hate them and research them as much as possible to destroy them, or you protect them with all your breath, OR you just don't care enough one way or another to research anything, and so you don't care about the issue. And if you don't care, why should you be asked?
So one way or another, it forces the person to come to a decision ALL BY THEMSELVES about who is right or wrong! (A novel idea if I don't say so myself.) This is what I have been forced to do. Both sides propose convincing arguments, but in the end, the JW's had far too many holes to be right, in my opinion. There are still 10 million who haven't discovered the truth yet though. THOSE are the ones I feel for. (Unless they are good little witnesses, take the "reproof" right in the ass, never complain, never go out of line, and never suspect a thing, in which case it's not so bad then.)