We can either balance everyone out to low burst, or to high burst. Either way works. Except maybe stuff like affli and hunter.
A shadow priest who doesn't have 3 orbs (every spriest after every wipe except the ones not using mass res, corpserunning, and using x3 6 sec (= at least 18 sec) to kill critters to get 3 orbs). Even with 3 orbs, their burst is shit, which you cannot say about warlocks who have good burst. The only advantage the spriest has over destro/demo is no decay of resource. If it truly bothers you, you could go affli.
I really doubt Blizzard simmed affli w/o the hit cap btw. Not sure if they do nowadays.