If professors that teach programming classes are experts, why are they teaching instead of working for multimillion dollar companies?

Most of mine teach on the side.

because those who can't do. teach

Because they aren't, or do it as a side

Perhaps they just couldn't stand the quality of interns they were getting and decided to fix the problem at its source ;)

Lol I don't think you know how much professors get paid. And yes, many teach on the side

If you really thing teachers are the best programmers you either never had a programming class or never met a true programming genius

most of my professor is from the industry.. they have many years of experiences in their belt. Depending on your university on how to hire their lecturers..

It's amazing how teaching is so underrated. Good teachers needn't be geniuses at their fields. But they do need to know how to teach. You can be the best programmer ever but you'll be a terrible teacher if you don't know how to pass knowledge along.

Besides, if pupils surpass their teachers, that's a sign of a job well done! It means teachers have given them the right tools to learn more than it's feasible to teach!