When you go ask a teacher or an expert a question and they just throw the question right back at you with "I don't know, you tell me", I find that to be the least helpful response they could give. I understand that it is meant to inspire further research, but it seems a pretty blunt and aggressive way to get the point across. The message I take away is "Don't come to me with questions, ever, because there won't be answers. Go get excited about learning on your own. Not my job." I didn't come here with an idea or opinion that I want validated. I'm curious and I have no ideas. I already ran out. That's why I came to you. So give me your opinion or, at the absolute least, ask me a different question that should guide my further research. If I wanted "you tell me", I could get that from a sign on my wall, and cut you out of the process entirely. I won't come back a second time if you do that, even to tell you what I learned.
Mokalus of Borg
PS - It's a blunt refusal to teach in response to a real request for knowledge.
PPS - To me, there isn't a surer way to shut down curiosity than by refusing to feed it this way.