INFP here with a strong T. Was born in, left unbaptized in late teens (don't remember exact age, just slowly drew away). Reason: My type tends to value authenticity. Once I learned the truth about the truth, I never felt at ease with the Witnesses. Also, I could never reconcile my 'independent thinking/feeling' personality with the nature of the religion. The religion clashed with my ideals.
I find the Witnesses cater to SJ type temperament. The doctrinal, rigid nature of the religion tends to attract those who value structure above all else.
Of course there's plenty of NTs and NFs that stay in and SJs and SPs that leave. I think the motivations are different. Intuitives are theoretical thinkers, and are more likely to question doctrine. But many may suppress these thoughts due to the org's guilt tripping, and ties to family. SJs and SPs tend to feel more at home in an 'organization', but may leave due to a certain event that triggers doubt. It may be an experience with an elder, a shunning, etc.
Of course these are all generalizations from my own experience, and may vary in individual circumstances. I find my relatives who are SJ/SP function better in the org to an extent (though they don't seem truly happy), while my relatives that are N tend to fight their temperament. I think there's a great deal of cognitive dissonance among Ns who begin to analyze and dissect the doctrine.