Well it's kind of tricky; how refined would we want to make each thread? Obviously for the regular adult work, a vanilla thread, a birth thread, and a furry thread all make sense to keep things segregated for those who find one subject or another squicky.
But do we split things up further? Should we cram all the loli content, birth, furry, etc. into one thread so that they don't clutter the site, or do we keep things split so that we don't have people forced to look through content they don't like? I mean, we have hide buttons, but it's so much easier to hide an entire thread than it is to hide each individual image you might find distasteful, especially if it's mixed in with content you enjoy. On the other hand, how much furry cub birth art is there going to be compared to plain loli birth art?
I dunno, just my thoughts on it that actually don't solve anything.
Thanks for the edit FastFlame. ^^_
A significant chunk of the community doesn't like loli stuff. People should be free to post what they want to post (within reason), but at the same time, people should be able to easily not look at things they don't want to look at.
Aside from that, any thread subcategorization is left to the discretion of the userbase, because really, this is their site, the staff is just there to make sure it doesn't explode. And if they want to make more and more intricately categorized threads, well, who are we to stop them? It makes things easier for people trying to find a particular niche of something, after all. :)
However, the problem arises when it becomes redundant.
We could have different threads for specific tastes, but how long before those threads become forgotten (like what happened with the last PregChan)?
While we could do that, I advocate posting those sub-categories into a single related thread.
For instance, this thread, the avian oviposition thread, and the pregfur birth thread can all be posted under the Pregfur thread. Aby posts the users don't like can be hidden by clicking the "Hide" button next to the file.