Way back when the games forum was created, someone tried making bunches of threads with titles like counter strike or halo, and the only content in the thread was a copy and pasted description of the game from wikipedia and the words "talk about said game here." Topics work better when you allow them to be created when the need arrises rather than when you try and force all discussion into a broad topic. One broad topic gets easily filled with confusing subdiscussions, it's a lot easier if you just let people make seperate threads about steam ids, garrysmod, tf2, VAC, hammer, and whatever else they want, and it's really actually better organized if you think about it this way.
At least, that's the way it always appeared to me. I could just be full of hot air. We were able to relatively contain discussion of RTB to three or so topics.
I digress. If people don't want to post in your topic, they won't.