There's certainly no question about propriety. If your question should be closed, it probably should be closed. But there are a few options:
Delete. If you completely messed up and your question was a problem caused by you, and it's never going to be useful to anybody else, you could nuke it.
Answer it yourself. I've actually had pebcak issues that I've solved, posted the answer and have since turned out to be very common issues. Posting the question and answer helped other people.
Accept what would have been the most useful answer. Sometimes I'll do something very wrong, float a question out. I'll get a few valuable (but incorrect) answers back beforeI notice that I accidentally moved
/etc/to/bananahammock/.An answer of
sudo mv /bananahammock /etcis not going to help anybody else because few people are as stupid as me.So then I look at the answers that were there. People suggesting good diagnostic issues that could help the next person in a similar situation. It's not just a case of clicking accept. If you pick something useless you might lead future visitors up the wrong path completely.
Or vote-close it, as you suggest.
You just have to think what's most useful to other people. What option delivers most value?