I believe there is no such thing as too open-ended a question to ask an interviewee. If you're asked something open-ended you have a glorious opportunity to define the scope of that question yourself, and to frame it in terms of things you know. Better still: you get to throw the ball back in their court by asking supplementary questions.
The point of such an interview question is to foster dialogue.
Yes. I agree with this. A strategy I employ when interviewing is to run with the first open question. It informs the interviewer about my knowledge and experience and gets me out of the majority of senseless tech questions.
The point of such an interview question is to foster dialogue.