As embarrassed as I am to admit it, 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.
Because you can pick up all talents that contribute to DPS even before you hit Level 80, it becomes a matter of gear scaling after that. In most cases, similarly geared Retribution Paladins in a raid will put out nearly identical numbers with few exceptions. Unlike other DPS classes where the spread can be wide owing to particular talent choices, differences in rotation, gear, and play style, Retribution Paladins have the relatively simple task of resolving priority when an ability comes off cooldown. There are no combo points, no freeze effect bonuses, no procs to wait for.
This isn't to say that Retribution is one-dimensional. It's not. Particularly in PvP, Retribution can reach deeper into its bag of tricks with stuns and incapacitate effects, instant Turn Evil, and a plethora of survivability and anti-cc abilities that you often won't bother with during raids. That said, there isn't anything particularly creative about how Retribution Paladins kill their opponents. It pours on damage. Prior to 3.1 that meant quite a lot of burst. For one glorious week, that meant ranged burst with Exorcism, too.