[xanados]

I think this would be ok if they said upfront that this is a simulation of a meeting and so to pretend that you are someone attending the meeting, and so explicitly take it out of the context of an interview. When I've been interviewed, we are often friendly toward each other and it's not uncommon for them to just want to chat and go on tangents, especially for throwaway questions that assess fit and culture. And you wouldn't know as the interviewee if this was such a throwaway question.

Basically, no matter what reasons you have for thinking people should do the right thing, you have to keep in mind that their reference set for YOU is all the people who have interviewed them in the past, many of whom were likely dumber and less competent than you. They are going to be acting accordingly.