That question is designed to show how superior the intervierER is to the lowly interviewEE
The ability to determine another person's destiny is a powerful drug! Don't OD on it, blowdart
Ah it's a good excuse that when you don't get a job isn't it? But frankly is a load of bull.
Do you think I want to spend 3 hours travelling to and from the office to go through what is a painful process interviewing someone just to show off? No. When interviewing you'll find that most people want the interviewee to pass, they're looking for someone to fill a position, there is a need for another body.
What they're not looking for is someone *wrong* to fill it.
Minh has a very valid point.
The question is a classical "halo effect" one, where the interviewer is looking to impose their perceived superiority on the candidate. Whilst this can go badly wrong in a number of ways, fundamentally it doesn't really assess the candidate ability for the job and just wastes everyone's time.
Where you really see it in reality is interviews where the interviewer talks most of the time. If the candidate isn't talking for at least 75% of the session then the interviewer is not doing their job right. This is where a lot of tech interviews fall down - deeply technical people are fundamentally not good at probing people's competencies. Instead they cover up their lack of social skills by talking about their comfort zone.
I've been interviewing for quite some time, and my conclusion is that focusing on pure tech in an interview is pretty pointless. You can always teach someone technology if they have the ability and the intent. Teaching someone common sense, interpersonal awareness, collaborative teamworking, and a positive work ethic is impossible though. So the latter is what you really need to focus on as an interviewer. And there's no specific question for that - it's not binary (which again is why deep techies are not ideal personalities for recruitment).