One of my interviewers at Tulane was sort of like that. I don't think he smiled once, he had a stone face each time I finished answering a question, he questioned how I got the MCAT score I did (like did I have to take it multiple times, take prep courses, etc.) and topped it off by insulting my undergrad school. 😡 It was kind of intimidating, but mostly it turned me off to the school.
I'm not sure why some interviewers take this approach. We may just be interviewees, but we still had to work hard and spend a lot of time and money to get to this point, and a little courtesy would be nice.