See, that is where you are wrong.
This is practically the sole Online community for SE players. Shrapnel is very supportive of non-SE4 discussions here. It is not just a place to discuss SE4, it is much more. Trying to limit discussions to just SE4 would probably drive 90% of the community away.
The Shrapnel General forums would not be a good place, as it would require constantly browsing two separate subforums, which is a pain.