Possible Duplicate:
Full contact moderating
Is getting a bad/poor question off the main page so important that it's worth closing a question even before it can be answered? That behavior just encourages "The fastest gun in the west" race where any flaw in a question gets the "close" gun drawn on it. The response is usually, "It pollutes the main page" which seems to be another way of saying, "It makes it harder to get the first answer in to all those questions."