While the emotional manipulation that we become subjected to upon leaving is, obviously, in large part due to explicit encouragement of manipulative tactics from the cult (i.e. shunning, telling people "we miss you" all the time, only calling when there's some special meeting we're supposed to go to, etc) I suspect that another significant component is just the level of emotional immaturity that the cult fosters in people in order to control them. Things like the culture of "stumbling" teaches people to blame others for their emotions - if someone does something that's not prohibited and you have a negative emotional response, they've stumbled you. Their advice for dealing with strong emotions is also terrible - essentially JWs are told to push their emotions aside and wait for god to fix it. So, instead of learning to take responsibility for their emotions and face/address them head-on, a culture of hiding their own emotions from themselves and blaming others for any negative feelings arises.
All this comes into full swing when they deal with people that have left. They refuse to acknowledge that they're sad because they're being artificially restricted from seeing someone and take responsibility for their own choices and feelings - instead they feel a bad feeling and blame the supposed proximate cause (which, by habit, is another person) and that person becomes labeled as bad. Then, when they engage in the instinct to seek empathy, they're so out of touch with their emotions that they can't tell you how they're feeling and take responsibility for it - instead they simply try to make you feel how their feeling via emotionally manipulative letters, phone calls, emails, etc. And because they've already labeled you as 'bad' and 'guilty' they'll refuse to acknowledge their immature behavior even if it's clearly pointed out to them because they're on "god's side" so they can't possibly be even partially wrong in the situation.
As I'm getting out more into the world and interacting with a range of new people, I've run into some other sorts of very controlling people outside of the JW cult - the more exposure to this sort of thing I get, the easier it is to see how a controlling cult-like system could spring up completely unintentionally out of a combination of emotional immaturity, insecurity and veiled narcissism. Some people just learn subconsciously that they can get people to do what they want that way, and don't even realize they're doing it. With JWs it's explicitly trained into them, but that doesn't mean they're any more aware of what they're doing.
So, while I refuse to have people in my life that are going to treat me in such manipulative ways, more than anything I feel sorry for these people that are floating through life with the perception that their emotional state is completely out of their control - being blown about by the winds of the world around them. We're all quite lucky to have escaped that.
