the human illu passive isn't any use at all for pvp, but it is nice in pve. Why? Having -10% malice allows you to equip other certs rather than -malice ones allowing you to make up for the lost crit rate or dmg.
Remember that not all tanks are aggro machines(some of them dont understand why its important) and far more commonly in later game, may bosses have a malice reset skill that can cause problems if tank is waiting on provoke cooldown. Yes, some tanks are bad, some make mistakes, others suffer lag.
This is more apparent in trials where mobs spawn during boss fights and you dont want to take aggro off 2nd tank or off tank.
Remember in pvp illu's main purpose is crowd control rather than outright dps.
I understand and admit that human passive isnt the BEST choice but it's still useful.
In exchange for not having a great passive here, humans do have some great passives on other classes like the stun chance on MA or crit rate on sami. They gotta balance out the races by making each good at a few jobs, and less so at others.
As for levelling classes for warlock, it wont take long. PLay the highest requirement class as your main and level others in arenas and you'll get warlock unlocked fast, For example, my warrior went from 5-55 in about 2 weeks with some casual arena playing.