That has less to do with professors' personalities than with the nature of their teaching.

The nature of their teaching matters but I place specific emphasis on the professor's personalities:

I am also more at risk of harsh treatment for political reasons. Given that their way of thinking is less like mine I am less able to predict what sort of things will piss them off and so provoke grudges more easily. I may say something that seems obvious to me but incidentally undermines something they care about. Once that happens I am not all that talented at making bitchy people not be hostile. My instinct is to avoid situations where I am potentially vulnerable to capricious whims.

The effect of personality is real. And I am not merely talking hypothetically here. It can bite me in the arse if I'm not careful. It is all too easy to overestimate how similar people are to ourselves and doing so comes at great price.