I totally agree with TheTXI when he says,
"Once you post a question it is not
exactly YOURS in every sense of the
word anymore, it belongs to EVERYONE."
However, there is an exception to this. If after a certain amount of time your question doesn't have any answers, you should be able to close it.
For example, I asked this question over a month ago. It got 16040 views as of today, but not a single real answer. I'm pretty sure no one is going to meaningfully answer it, and I also no longer have the need for the question to be answered - nor the facility to check if a submitted answer is correct, even if one showed up. There are three reasons why I should be able to revoke it.
- Revoking the question weeds out pages that are unlikely to add insight to users coming from google to seek answers.
- Long-unanswered questions actually deter people from using the site. Every time I google a question and come up with some unanswered question on a forum somewhere, I think to myself, "well, I'll never post there - this community must not be very active on this topic."
- Inexperienced users like me have two incentives to offer to people to answer their questions: starting a bounty and maintaining a high accept rate percentage. Inexperienced users will naturally have less points to start a bounty with, therefore it's very important they maintain a high accept rate percentage in order to encourage people to answer their questions. If you ask a question that you're pretty sure is going to lay fallow, you shouldn't have to live with the decreased accept percentage; you should be able to close or revoke the question.
It makes total sense to have to wait until five people notice to close another person's question - the community use case there is assuring that questions don't get prematurely closed by other people unless the community really decides that it's flamebait or a rediculous question. This proposal, however, services an entirely different community use case - cleaning out questions that are just pollution.
If this change is not instituted, it will give users a (negative) incentive to simply "edit" their posts to turn them into entirely new questions. If that incentive is your idea of a feature, then we should make it clear that users are expected to rewrite their former useless questions to keep their accept rate up.