I have a good friend who plays a particular game and writes some of their information and adds modules, etc. (all as an unpaid volunteer) and I keep telling him to write his own game (as he complains about this one sometimes). He's a computer programmer and is big into writing/correcting wiki pages too, etc.

I wouldn't necessarily think in terms of taking down another site, if you have an idea for a game, I'd work on it because you would enjoy doing that. I don't think one can predict what other people will do enough these days to know how things play out; I mean look at how poorly poor Facebook did with their IPO? I think nowadays that just working hard on a passion is what it is about instead of trying to predict the market or invent things for the market, etc. The market is too fickle.