I have to agree with the passive-aggressive mentality being common. I think all the nervousness surrounding interviews shows how adversarial they are.

For how aggressive some interviewers are, I believe half of that aggression comes from the interviewee. If they start with some passive-aggressive questions and you get defensive then you're just as much a barrier to communication as them. When you read someone else's answer to an interview question and are struck by how well they answered it is rarely because they had a witty answer that stunned the interviewer, but rather that they were open, honest, and entirely non-aggressive and so were able to show how smart they really were.