Last modified: 2011-03-13 18:05:02 UTC
On Special:Wantedcategories, link the number of items to Special:Whatlinkshere.
That wouldn't make sense; Special:Whatlinkshere contains no useful results for categories, or rather, it doesn't contain links from categorisation, but direct links to the page.
Special:Wantedcategories link to the most sensible place - the categories themselves, which will list their members regardless of whether or not the page exists. The members of a category, rather than any pages that link directly to it, are the metric when deciding what description it should have.