I think a lot of your responses are half-proving my point. You say it is easier to get good at MW games (and in a shorter amount of time) compared to CSS. Ruplayer gave an example where he said he often had a 6kdr, and I remember having a similar experience. But for us to have such extremely high kdrs, the kdrs of most other players have to seriously suffer. It suggests that many of the players have to be at a significantly lower skill level than us. I remember getting scores around about 40-3 very consistently on Free-For-All mode (and that was within the first month of playing).

Maybe on average the skill level of people in CSS is greater, and that makes sense because it's an oldish game, and many of the players who are still around have been around since the start. But regardless of that, I still make my point that tomix simplified (thanks ;D): "In CSS, there are more limitations on how good a player can get, relative to other players. It is easier for a talented fps gamer to get extremely good at MW"

I understand that it may take longer for most people to get decent at CSS, but that's not actually what I'm trying to argue about.

I do agree with spartacus though, there's much less social interaction/less of a community. It probably also has something to do with the match making system in MW2 and 3 (I think?), as opposed to the dedicated servers that CSS uses.