What is really crazy about this though is that sometimes it really is the interview setting, as people unused to interviews can, at times, emotionally collapse. I have seen people who are actually good programmers get wrecked by simple questions because of their inability to handle stress, and how the lack of interview practice turns a simple exercise into a hellscape.

It's not as if testing for performance under stress is useless: Tough on call rotations happen, and you might need someone that does well under pressure at 3 am in the morning. But the picture you get on a screening isn't as clear as it appears.