A big enemy of the warlock is the way EQ2 agro control works. It seems to have a system of decay that drops your agro faster the higher you are on the list, as well as increasing it faster the lower you are.
Case and point: Amorphous drake, Zerker tanks one of the blobs for 1-2 mins while blob 2 dies. Dps runs in on blob 1, a monk uses all his combat arts, or a warlock starts chaining debuffs and nukes as if agro didn't matter... for some reason, even though the tank may have 60,000 hate, you can still pull agro after bursting 10k dmg.
I've never had a warlock in my raid force, and one of our wizards is betraying. I've looked at the warlock spells and it seems that a reason warlocks may pull agro is related to the damage of their spells. Wizard spells from what I've seen are more spread out. That is, higher damage on a couple and lower damage on a couple. But warlock spells are mostly around the same damage.
Also, you can't base hate off of damage. The more often in a small period of time you hit a mob, the faster you jump up the agro list. If you were to have spaced out those attacks, and maintained the same dps, you'd be much lower on the list.