I also just plain old like it... It makes sense to me. I never got hugely into achievements but I liked the Gamerscore on the 360, it was a good proxy for how much you had achieved overall on the console, and how far towards 1000 you got on a game. Most games you'd get ~ 500-600 out of 1000 just for beating the game, and then you could go out of your way to master it and push towards 1000.