For example, if you come across a picture of an antelope you want to share, it is better to share it to /s/pics than creating /s/antelopes, post one picture and continue being moderator of dead sub.
It really can hurt the site. It occupies the slots someone else may need in the future. It hides the content and makes it never reach the front page.
The system of subforum is bad for this practice. If we had tags like hubski, it wouldn't matter. But it is quite a problem for reddit-like forum organization.
"Subfox"... So, we're settled on that name then?
I think we should just call them subs. And then the mods can all be called doms.