I got my fun from balls out running and firing rockets and rails in the chaos of free for all, and CS offered what was essentially the 'we're all campers' version, which wasn't fun at all (for me, at the time).
I didn't want to simulate anything, I want(ed) chaos, instant respawn, lightning reflexes, constant motion. Maybe I do have ADHD.
CS has stood the test of time though, so respect for that.