I think the question is, how selective do you want the QSQs to be? If one author and/or story is nominated in half a dozen different categories, how likely is it that s/he won't win something? Of course everyone likes winning, but frankly, I think it's a little less meaningful when there are so many categories that the committees can give something to almost all of the top contenders.
In nominating, people need to remember that we don't allow a fiction to win more than one category, and they can't win multiple years either. Once the best stories are gone, others need to be nominated in their place. Is there enough great writing out there to warrant another pair of categories?