Like the quote from Orwell shows above - this problem goes well beyond JWs. I find it interesting, even on this forum, that people latch on to their beliefs no matter how many hard facts show their beliefs may not be so certain. I wonder if that's just a trait that is carried over from being a JW.
Despite all the nutty beliefs of JWs - the main downside is the shunning policy and the blood doctrine after that. You take away those two things and you have, more or less, just another religous belief system. I mean without the DFing - then you can take blood, disagree with doctrine somewhat openly, and hold ideas that are not endorsed by official JW doctrine if you so desire.
In the book "Mistakes were Made (but not by me)" by Carol Tavris - it spends some time emphasizing this idea by focusing on the many false accusations of child abuse were that propping up in the 80s and 90s. Many child psychologists would back a claim of child abuse, only to later find indisputable evidence that such abuse never happened. However, instead of retracting their testimony, they often defended their position even more so. Rarely did any of them admit their error and faulty thinking, despite that their support of false claims put many innocent people in jail. It really is a great book - and it backs the idea Barbara is making in the OP.