In product work, we often have to ask “why?”, but if “the why” isn’t obvious to the person you’re talking with, they begin to question their existence and their motives. It’s a much weightier question than it’s intended to be.
An alternative to this is saying “Tell me more,” because that’s what we’re really getting at. Perhaps the why isn’t apparent to the person, and by saying “Tell me more” we can get there just the same, without causing some miniature form of existential crisis.