At the university level in the US, few faculty get any kind of training before they are expected to start teaching. And the teaching requirement is more or less “do no harm.” If you’re at a research university, which includes many publicly funded universities, then your career trajectory is based almost exclusively on your research output. I could go on, but it suffices to say that it’s not surprising that the teaching could be better.

That said, most institutions have teacher training resources for faculty. I was fortunate to be able to work intensely with a mentor for a summer, and it improved my teaching dramatically. Still, teaching is hard. Students sometimes know—but often don’t know—what is best for their learning. It’s easy to conflate student satisfaction with teaching effectiveness. The former is definitely an important ingredient, but there’s a lot more to it, and a really effective teacher knows when to employ tools (eg quizzes) that students really do not like.

I am frequently amused by the thought that here we have a bunch of people who have paid tons of money, set aside a significant fraction of their time, and nominally want to learn a subject that they signed up for; and yet, they still won’t sit down and actually do the reading unless they are going to be quizzes on it.