Warlocks have no damage niches like a typically balanced class. Instead they excel at dealing every type of damage more than every other class. Burst + sustained, Single target? no problem. DoT cleave? no problem. AOE? hell yes. Normal non-god classes have a weakness in one or more of those areas whereas locks do not on top of providing 3 raid utilites : gateway, healthstones, and soulstone rez.
As if that's not enough they can STILL cast while moving, have a sort of immunity + 2 whole tiers of talents dedicated to personal survivabilty and finally personal port.
Warlocks just get it all with no drawbacks all because of "low representation". Idk how that justifies one class being literally god of the game for an entire expansion and needing to have 3 viable specs on this one pure when most classes barely had one