Gordon wonders why we do not go all the way and sell leveling and raiding games separately. Many people have taken the option of simply ignoring the raid game that is duct-taped to their leveling/achievement game, the same way you can completely ignore PvP in most games. This would be one of the reasons I had a short tenure in WoW: the gear resets alone made it feel enough like a sequel rather than an expansion, so adding synchronized online dancing was some completely other game wrapped in the same box.
I bought the Orange Box long ago. It did not make me complete Half Life 2 before playing Portal.