Why cant wow keep the class more balance

i should be able to play any dps in high keys or raids! affliction is so much under other dps its not playable! i was doing 160-200k in keys before s4 now im running 140 top where other classes are running 260k. there’s no need for mata classes! i work a lot and only have time to play one guy not jump form one class to the next. keeping every class within 5% shouldn’t be hard and one of your priorities. i know a lot of ppl that are tired of this inconsistency!