You're right, the forum is very slow compared to what it once was. It is a sad thing to admit, but a great deal of what drove TKC to stardom was the fact that very few such communities existed back in 2003 (there still aren't that many, but its not as much of a rarity as it used to be).
Another thing that prompted more membership was the constant drama between us, the Gather of Developers forums, and for a time the Gathering of the Banned. Man, those were the days... it was a gamers wet dream of an online soap opera where something new and more scandalous happened just about every day.
Although the hacks have - and will - always be important for the success of TKC, it was the human factor that really breathed life into this community. And as much as we'd hate to admit it, the occasional detractor and whiner who hated TKC also encouraged participation. After a while the GoB and GoD forums both disappeared, and for the most part so did the detractors here, eventually.
Without the human component, the draw for your average gamer to come to TKC for anything other than to download the latest hackpack just isn't there. And that my friends, makes me a sad panda...