I don't really agree with your point. In the example, the candidate did the interview for as long as he/she thought it could turn into something. As soon as he/

I don't really agree with your point. In the example, the candidate did the interview for as long as he/she thought it could turn into something. As soon as he/she realized that they ask questions that are completely irrelevant to the job (in his/her eyes, at least), the candidate let the interviewers know that it's not the kind of job, team, priorities the candidate wanted. Nothing wrong with that. Wasting their time would be to continue the interview process and answer questions you think are pointless for the position at hand. It's something you can do when you already have other offers or your current position is good enough (meaning it is better than what the interviewers can offer). When you know you won't take the job, it's okay to cut the interview short.