It is this very principal that allows reverting and rollback to take place. However if a page is vandalized over a long term (gradually vandalized by n00bs and anonymous users) it may appear totally irredeemable and either have a 30 day maintenance template slapped on it or be put on Votes for Deletion. Which takes me to this. Check the history DAMMIT!
If you come across a stupid article, a stub, cruft or any other article type that we at Uncyclopedia generally prefer to not have included in our statistics. STOP! before adding a VFD template and creating an entry, check the history! If you see a version of the page that is funny and well formatted it takes 5 seconds to restore it. If you can see that the article has at no point been funny, then knock yourself out, add it to VFD and the voting will take place.
edit Maintenance templates
By and large you can't simply vandalize a page into needing one of these. Redlinks for example appear as other articles are deleted and are actually inspiring. But as with VFD if you can see a problem with a page, check the history to find a better version. If all seems bad even in the history add your tag.
edit Before deletion
Although seemingly unrealistic if an admin could check the pages in either criteria before deletion a lot of innocent and vandalized articles could be saved!
edit So in summary
Checking the history if often the difference between seeing an ok article being huffed and it being saved. It's easy and only takes an extra minute of your time!