Unfortunately, some insecure developers sign up to be interviewers precisely to feel superiority and power over interviewees. I've both worked with and been interviewed by some of these people - they seem particularly prominent in the valley. Anecdotally, Google was the worst of the big tech companies with cocky, condescending interviewers that came in wearing Ivy league sweaters. By contrast, all of my interviews at mid-level tech companies were equally difficult technically, but much more pleasant and engaging.