Really ? Wow interesting that it isn't stated anywhere ingame. See thats what i don't like about Blizzards stat game. They don't really tell people what stats do and they give you no hint what stats are important for what class/spec. Would it be so hard to have an ingame hint that says "Hey, Destro Warlocks need Int->hit->mastery->crit->haste".
But no, some theory crafter has to figure that out and i have to look it up on some website instead seeing it in the game i play.