Originally Posted by
animeprime
Player warlocks are supposedly "fighting fire with fire". They never let themselves become servants of the burning legion or offer their services to them like Gul'Dan did. There is the constant threat of them falling over to the dark side, so supposedly their own covens and councils have hit teams that will take them out if they fall, so it doesn't make them look bad as a whole or cause a lot of damage. Most of the old vanilla class quests and trainer dialogue made it clear how you had to always be on guard that you don't delve too deep. Actual burning legion warlocks have no such compunction and only crave more and more power.