I do it a fair bit. Sometimes to start a conversation, although that tends not to work that well. Sometimes because I’m having a discussion in comments, I’m asked a question, and I think it’s useful to get the answer out there. Less often, because I want to get some information out there of my own accord.
Quora policy says there’s nothing wrong with that, and I don’t think there is either. I own the answers, the community owns the questions. I might as well contribute to the community the questions that prompt good answers out of me.