There are two problems that prevent more people from posting in these sub-forums.
One, is that many of us who have been here for a while joined originally when we were much younger and had a lot of free-time on our hands. I know that for myself that is, quite unfortunately, no longer the case. Thus, I spend much less time on forums.
Second, there are like 30 sub-forums now. It's a big wall of text and so most people have no desire to keep scrolling down. I myself have a hard time getting down here on the rare occasions I do manage to pop back in.
