Prior to 1.4Beta3 on the English version of Wikipedia, if someone created an
article Foo that had a category e.g [[Category:Foobar]] and Foobar did not
exist, then if you went to create the Foobar page, the article Foo would appear
along with the edit window to create the category. This allowed the editor to
backtrack and fix an article if Foo should really go to [[Category:Foo Bar]].
Now if you get a report of non-existent categories with articles that link to
them, they are impossible for a user to track down. The What Links Here does
not work as well for this instance. For example. Go to Robert E. Lee from above
see the category:People from Virginia... If you go directly to People from
Virginia, it is impossible to know that Robert E. Lee is the one linking to it.