It's funny that you can not only answer your own question, but also flag it.
Why one would do this? Why this possibility exists at all? Is it a joke?
I've flagged some of my questions in the past for moderator attention when there's various issues like Sathya mentioned. Flagging a question doesn't necessarily mean that there's something inherently wrong with the question itself; you can use it to bring attention to anything going on in the "thread" that is otherwise bad.
Now of course, if people say that my question needs clarification or other improvement, I'll just edit it.
If a question has answers, you can't delete it, so if I agree that it's off-topic or not a good fit for SU after the fact, I can flag it to be closed, or vote to close it once I have enough rep.