This is an honest question. When I ask this, I specifically want to know what classes they play.
I honestly believe, they do not play support classes. (i.e. tanks and heals).
For tanks this is due to the seemingly obvious problems in class design. DRK is put in a position where it has worse CD's than PLD (arguably also WAR's that use inner beast well).
However, this pales in comparison to AST, who straight up under performs compared to WHM and SCH. The shields are weaker, the heals are weaker, and I am not even going to touch utility or dps which is abysmal.
For DPS. I don't know, the BRD/MCH nonperformance was obvious from the get go as BRD got about 30% of their damage from auto-attacks from the old barrage/2.0 system, so a buff of 30% would be a reasonable start for keeping performance equal.
This is more a plea. In WoW they actually consult and deal with top raiding guilds for feedback. The test servers iron out alot of issues before live. The developers actively play the classes they enjoy and are open about it. They are also quite honest about the fact that players will always be better than them at the game. It is time to consider some realistic testing practices and feedback systems, as in-house testing leads to bias (playing classes in an intended manner) and results that cannot be replicated by 1000's of players in just a few days of testing.