You wrote:

Almost by definition, the people who teach science are the people who (didn't want to go it|couldn't cut it) in research

That is probably true as a generalization, but I can certainly think of exceptions. I, for instance, think of myself as a good researcher, and very much enjoy teaching. I would happily teach at the high school or college level, but the sad truth is I can't afford it. I have a family and gigantic student loans to pay back, so I can't give up my good job in industry (which I also enjoy) to take a huge pay cut to teach. :-/ It says something very sad about our education system that I am in this situation.

Scott