To clarify, since JHM's answer is incomplete:
The pages on explicit material (both pornographic and paedo-ish) were attracting edits that overly glorified the scenes within the work, making it look like we endorsed it. (It didn't help that most of these works tended to not paint these things in a negative light.) This made a number of tropers uncomfortable...and quite a few other people uncomfortable too, most notably the AdSense (Google's ad service) people.
It didn't help that the vast majority of these works were niche works, meaning few editors were working on each page. The fewer editors, the less Wiki Magic
to correct for such problems. So a lot of these went undetected for a long time.
Thus the cleanup. The only other alternative would be to have the moderators and/or tropers, at least in the short run, run a round-the-clock watch on such pages, in order to keep them from becoming too endorsing or, worse, too explicit themselves. Obviously, since that would likely require more people to read/watch/play most of the works in question, they naturally shot that idea down.
While it would be nice if we could provide a full documenting of every type of work, the inevitable price of freedom of creativity is that some people will use it to produce works of questionable taste. *
These subjects are just too hot to handle right now, so to speak.
edited 7th Oct '12 6:55:37 AM by TotemicHero