As this subject has been done to death on Meta Stack Overflow, I'll be blunt.
The definition of closing has been made abundantly clear almost since the inception of the network:
It’s important to note here that closing a question is a step on the road to deletion. Closing is effectively “nominate to delete”, as a question that can’t be answered is no longer truly “alive”. That said, some closed questions should be kept around. For example, duplicate questions that have totally different wording are sometimes useful. With the duplicates, people can find either variation with search terms and link through to the original. The majority of closed questions, however, aren’t particularly useful and are much more likely to eventually be deleted.
I flatly disagree that closing is merely a friendly suggestion to edit or improve, and repudiate the notion that most closed questions are even salvageable. Some are; that's why we still allow editing questions when they're closed, and give everyone with close privileges a set of parallel reopen votes.
Reopened questions are the exception to the rule. The vast majority of closed questions on any and every Stack Exchange site:
- Get asked by users who do not subsequently engage with the site or community
- Display little to no evidence of having read the faq or about page
- Aren't edited or improved
- Are never reopened
- Are eventually deleted
That doesn't mean that we should never try to help people who get their questions closed. Some people do "get it" afterward and clarify or clean up their questions and sometimes even go on to become regularly contributing members. But again, these are the exceptions that prove the rule. As moderators (diamond and community) it behooves us to understand how the system really works, to see and treat things for how they are and not how we wish they were.
As a community, we already edit questions that are slightly off-track but still salvageable. I've personally done this hundreds of times and I seriously doubt that anyone could say in good faith that I don't try. Closing a question means that nobody who saw the question could think of any way to fix it - at least not with the information available. Even if the question could be reopened after a phenomenal edit, it's not necessarily the wisest or most pragmatic course of action. It's just as easy to ask a new question, taking into account the lessons learned from the initial closure.
Closing means "this question does not belong here". If you change the question, then sure, it might then belong - emphasis on might. It's not a promise, and any expectation of constant hand-holding eventually burns out even the most committed members.
All of that being said, I almost always do leave a comment when closing a question regarding specifically why it was closed and, if applicable, what changes might get it reopened. And I encourage others to do that as well. But much like downvotes, an explanation not be treated as an obligation; the close reason itself provides a clear explanation and the faq has more detail.
See also: My question was closed! What should I do?