Speaking from my own experiences in dealing with my 2nd generation regular pioneer mother, I've trapped her in discussion on doctrine a few times, and the last couple times I watched her actually become physically uncomfortable. Her entire demeanor looked like she was in the room with a known rapist on the lamb. The crazy part about it is the entire time I remained calm and collective while she on the other hand started raising her voice, and her reputation is that of a reasonable and level headed person. It was fascinating in a sense, yet so very troubling to me. My brother and my sister are willing to discuss these things with me, although I'm hesitant to push too hard. My father wasn't a born-in, and he's expressed to me on multiple occasions that there are things in this religion that remind him of Babylon the Great. He even stated emphatically that higher ups in the religion remind him of the Pope. Him not being a born-in and making such comments leads me to believe there's still traces of his non-cult personality present.
My mother on the other hand is a lost cause, and to bring up doctrine and methodically point out the flaws in the WT's belief system, is too much for her to handle. I wonder at times if that plays a role into why the WT might be hesitant to discard certain key beliefs because they're all too aware of people like my mother. Are they concerned that it would be too much for some long time JWs? It'd be like pulling the rug out from under someone.