[chongli]

They most certainly don't welcome challenges to the basic assumptions on which their teachings rest.

Professors are trying to teach a class, not engage in a debate with a student. Challenging basic principles that everyone in the class are already assumed to have accepted is usually seen as an attempt to derail the lecture.

Derailing the lecture and drawing the professor into a debate with you effectively denies the other students access to education. It’s roughly equivalent to heckling a comedian.

If you want to debate your professor, do it on your own time, in office hours. If the professor is still offended and unwilling to debate then you have reasonable grounds to complain. Most professors I’ve met absolutely love to debate outside of class.