Why didn't 4th Job AoE's get a cooldown?

To top off your main topic question, 4th job AoEs burn up tons of mana even if you're level 200 or something, this skill will burn up almost all your mana if used up to two or three times, not to mention you're gonna need all the good pots to keep up with using this skill coz this skill also wastes money if you don't use infinity.
I dont think it's really cheap to my opinion.

Yes once new high level areas start coming out (eg. Ulu City, Time Temple), it would be better for everyone.