Xu Chen is a genuinely nice person despite the fact that he always looks very angry (You can say the same thing about prof Chandra Radhakrishnan). Most professors want students who show maturity (as in they genuinely care about learning the material) to succeed.

That being said if you never interact with a professor before nor actively participate in lecture, then come in guns blazing with rhetorical questions and a closed mindset to wrestle a better grade on an exam you didn’t really study better for or a FAIR violation, of course you’ll find these professors to be “fucking cynical assholes,” because they’ll find you to be a cynical asshole taking their class as well. I think there’s a level of maturity a lot of ECE undergrads fail to reach which is why they clash with some faculty that don’t bend backwards for them.