Sometimes when a question is closed, different people have a different reason for closing it. You can see this while voting: there is a count in the margin saying how many votes of a given type have been recorded.
However, once the question is closed, not all of this information is retained. Often, only one reason to close is stated in the 'Closed' dialogue below the question. Not only is not all the information passed to the OP (or certainly to the world); it's also harder to fix multiple problems at once.
Wouldn't it be better if a question needs 5 close votes of the same type (e.g. 'Too broad' or 'Off topic'), rather than any 5? What are some benefits that the current system has to the system I propose?
If not that, wouldn't it at least be beneficial to show all the reasons for closure, and not just the ones with two votes or more, cf. Todd Trimble's comment below?