Ironically Marauders can be called relatively balanced on high levels of play.
They suffer from the Retribution Paladin syndrome that plagued WoW from Vanilla. This class\spec had relatively simple ways of doing heavy frontloaded damage, had a 6 second stun on a fairly accessible cooldown, and cooldowns that provided immunity to movement-imparing effects, they had a 12-sec full immunity shield, and they had the ability to heal themselves.
Even the dumbest, most talentless RetNoob had a very good chance against the "lowest common denominator" player of another class. But it could easily be disassembled by a player who knows what they're doing. Marauder cooldowns do constitute a similar "foolproof". The difference is, however, that to learn to fight RetPaladin, you didn't need a lot of effort. With a Marauder, however, the best way is to play it yourself.