Agree. I have taken classes with over 40+ professors (close to 50, but I have also taken two or three classes with some profs) in my undergrad and grad school. Out of them, I can recall ~5 being pretty good instructors. Being a professor does not guarantee one is a good teacher/instructor.

The thing that sets apart good instructors from mediocre ones is the passion they have toward teaching (esp. the good ones seem to have empathy as in they want students to succeed and understand the materials that the instructors themselves probably took a good amount of time digesting when they were in students' shoes).