I do think rationality is a niche. I had a conversation with a not-particularly-bright administrative assistant at work where she expressed the teachings of Jehovah's Witness as straightforward truth. She talked some of the chaos of her life (drugs, depression) before joining them. As I expressed the abstract case for, essentially, being careful about what one believes, it seemed clear enough to me that she had little or nothing to gain by being "right" (or rather adopting my opinion which is more likely to be true in a Bayesian sense) and she seemed to fairly clearly have something to lose. I, on the other hand, have a philosopho-physicist's values and also value finding regular (non-theological) truths by carefully rejecting my biases, so I was making a choice that (probably) makes sense for me.

When my 14 year old daughter (now 16 and doing much better) was "experimenting" with alcohol, marijuana, and shop-lifting, I had a "come to Jesus" talk with my religious cousin. She told me that I knew right from wrong and that I was doing my daughter no favors by teaching her skepticism above morality. I decided she was essentially correct, and that some of my own "skepticism" was actually self-serving, letting me off the hook for some stealing I had done from employers starting when I was about 15.

I view rationality as a thing we can do with our neocortex. But clearly we have a functional emotional brain that "knows" there are monsters or tigers when we are afraid of the dark and "knows" that girls we are attracted to are also attracted to us. I continue to question whether I am doing myself or my children any real favors by being as devoted to this particular feature of my neocortex as I am.