The truth is that Retribution has a pretty low skill cap. This is an old accusation, but one that has quite a bit of weight in it. Although it used to be primarily an auto-attack class in PvE, things changed with the introduction of Divine Storm and now Exorcism in Patch 3.1. Still, many Retribution Paladins can faceroll their way to good DPS because, well, the class design is really easy to play. There are buttons that you press to do damage, you wait until cooldowns are up... rinse, repeat.