Actually it's not that hard to count them if you copy and paste into Excel. Probably took Jon about 30 seconds.

I read using the "New Messages Since Last Visit" option, and there are loads (highly technical statistical jargon) more posts to BS: threads, so it gives a sort of skewed impression.

The thing with the prefixes is that sometimes it seems people try to select ANY label. "Folklore" for instance, is driving me nuts, and "Origins" is a close second. Things about music history, performers, jokes, yada, yada, ends up in "Folklore," and it ain't.
At least that's my opinion. And "Obit: My Sex Life" stopped being funny a long time ago, possibly before the first person used "Obit:" for something silly. That said, I don't change prefixes just because they bug me. Many times, threads (especially the BS/music ones) may wind up being about something we don't expect and it makes sense to wait and see what happens.