Why Is Stub Sorting Important?
Stub articles are generally short or below the high Wikipedia standard, or both. If they are not sorted, then it means they are less likely to be edited to higher quality as nobody necessarily knows the page is in need of attention. Even if a page is sorted into a category indicating it is in need of attention, such as the articles needing a cleanup, it is still not as good as putting it in a stub category. This is because stub categories attract experts in specific areas (chemists can see chemistry stubs for example), whereas generic cleanup and deadend categories do not.
Read more about this topic: Wikipedia:WikiProject Stub Sorting