Well, perhaps "useless" was the wrong word. But people are already whining that there are too many categories. (Which makes no sense to me: it's not like there's some limit on the number of categories we can create, and that once we've used them all up we'll be stuck.)
Although, I suppose, to be fair, if somebody is trying to find out something by browsing categories rather than by running a search, then finding hordes of empty categories would be kind of frustrating to them.
In any case, in my own work on fixing Ontario/Canada West/Upper Canada categories, I only work on categories that already exist and are populated. Like, if I find a "City of Melonville, Ontario" category, I'll move all the profiles that I can to "Melonville, Ontario", then delete the old category. But if I find an empty category with the wrong name format, I'll just delete it and not create a new one. (Or at least, not until I find a profile that belongs in there.)