Yeah, I agree; I have the same hypothesis that this is what people want. And it's a problem to assume and/or act like talking about anything other than specific coding experience is in any way insulting. That's not exactly a realistic expectation, nor is it a great attitude for getting hired.

Personality, behavior, poise, attitude and communication skills are absolutely relevant to someone's ability to do their job on a team. If you can't think on your feet or answer a question without a computer in front of you, and you start getting angry, how will you behave in meetings? That behavior is precisely one of things I look for when I ask candidates to think on their feet.

If someone assumes that being asked certain questions is "unprofessional", then that's a red flag and I'll be more careful before hiring someone like that. Now that I think about it, there's a bit of irony that if someone performs poorly on these kinds of questions, I'm likely to spend more time investigating that and asking more questions along those lines.