This has been said before, and I'll answer the same way I did then.
This is a community of players. Not everyone can go on playing the same game for years. Now, I started this whole "Let's Play.." thing when I did Slavehack, and I'll tell you why: If you want a community that will continue to grow, thrive, and not die, you need to be able to talk about other games, and play other games with other people in your community. That's what's going to encourage people to stay, as great as Toribash is. Why join up with a whole new gaming community, when you can play that game with people of the community you're already in.