I am compelled to write a bit about this at this late hour here in the US, because it is keeping me up.
The recent four year old thread on the Briggs Myers personality type test that was dug up, produced an interesting finding. Many here, (at least tested informally for), the INTJ personality type. This is significant, because even if many who took the test and recevied this result, did so somewhat inaccurately, it still does not negate the fact that many have similar personality traits that do not fit in well with what most humans "do". INTJs make up about 1-2% of the world population, and the fact that so many here tested out this way does matter. It is not a mere statistical anomaly. Anyone with a background in probability theory would understand this.
INTJs may very well make rational decisions easily, be particularly good at seeing the "big picture", etc., but the reality is, they do not deal with irrational behavior well. That includes their own irrational behavior, that they themselves are sometimes are susceptible to. Contrary to what some light hearted material on the subject might state or imply, INTJs do have feelings, they just internalize them. INTJs also do not understand irrational behavior particularly well at all.
Why does this matter? Because human relationships are not rational. They are based on emotions and intuitive hueristics. INTJs expect humans to deal rationally with each other at all times. Guess what, we don't. None of us do. For example, when we experience shunning from a loved one, (yes, INTJs do respond to love), it hurts like hell. We do not have a built in mechanism for coping with this other than our analytical skills, which are inadequate to understand this irrational behavior. So guess what, we spend much of our time on forums like this, researching, reading, meditating, and pain killing, (INTJs can be more prone to alcohol and drug abuse), to find an outlet and closure to the pain we are experiencing.
I would like to once again stress the point, that a statistical anomaly is not what we are seeing in these results. JWs make up about .1% of the total population, and only a subset of that number leave. A much smaller subset of that number, actually care to do any research, and understand their past experience of being a JW, as well as curious enough to learn the big picture theoretical ideas that INTJs generally gravitate toward learning. It is very likely that the high percentage of this type we see in the results is consistent with the audience we are sampling. Hopefully, this provides some clues in better understanding ourselves.