It seems this is true in teaching and politics as well. My first day as a grad student at Stanford, I was surprised to see my new professors make the front page of The Stanford Daily for their low marks as teachers. Strange, because they were such respected scientists.
So I asked one of them, the Dean of Earth Sciences, a fellow in the National Academy of Sciences, the president of the American Geophysical Union. He said the ratings are from evaluations the students submit right after the class. They lean toward how entertaining the professors are, how fun, funny, and easy they are.
But Dr. Cox said what he cares about is whether what they learned was timeless and important to them 20 years from now. That's the evaluation he wanted to see: what did his students think 20 years later.
I thought that so strange and a little bit crazy at the time. But there I was 5, 10, 20 years later, remembering what he taught us and thinking about how profound it was. It was boring at the time and I didn't see students lining up to take his classes, but looking back he taught the most important classes I ever took.