[emsy]

In competitive games (UT, Quake, CS etc.) you get better by playing and critical analysis of your and your enemie's playing. In WoW, you get better through, more or less, mindless grinding. At least so mindless that you can pay peons to do the work for you, so you can enjoy your level 100 character.

[Fomite]

Having once been a fairly serious raider in WoW, there's a ceiling in WoW wherein you no longer get better through mindless grinding. A level 100 character is nice and all, but serious end-game raiding or PvP requires more than just "Push button, collect loot."