PvP isn't balanced around anything, just be honest. Double frost DK holy paladin? Mages? Warlock damage? Ret paladins? Resto shamans? Earthshield? Feral's instant cyclone? Deep+ring? Holy paladins? Hell, we even have a enhacement shaman/resto shaman/warrior team at 3010~ rating, what the fuck is this?
There's no point in even arguing what the game is balanced around right now. This season was broken start to finish, even more so than s5, which is really overwhelming, but hopefully it'll go back to "normal" (read: slightly less imbalanced) soon enough.