I never even thought to ask <i>why</i> rewarding works better than punishing, or why intermittent rewards work better than predictable ones.

It didn't even occur to me that there would such reasonable answers, based on already-established principles.

I think I had a blind spot, something like: Because psychology is the product of blind, stupid evolution, don't expect "meaningful" answers to why the brain reacts certain ways, the answer will always boil down to "local pressures in the evolutionary environment."

But you can reduce myriad findings into more general, foundational principles, for the sake of efficiency and elegance, in psychology as everywhere else. Good lesson for me.

I don't know if your particular answers are right or not, but kudos for generating the questions.