Sometimes it happens that a question is closed hastily. Either some information was missing, but was later added, or because some (5) people did not understand an unclear (but still understandable question), or because some users followed other users' decision to close (because they are popular, for example).
In all cases, if the question does not really 'deserve' to be closed, there is the reopening process. I don't know what's the statistics, but I don't think it's too often that a question is reopened.
One of the reasons (apart from the obvious - that the question really deserves closing) is that people don't bother opening closed questions - that is, questions with
[closed] in their titles.
My suggestion is to add the number of reopen votes to the title, so that people know that there's still 'hope' for that question, rather than ignoring it. For example
[closed, 2 reopen votes]