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

There's a very easy way to fix this.. You know those new monsters and maps in MapleSEA? Why can't gMS have higher-up monsters that are about a Skelegon's level, but not weak to Holy, but instead weak to Fire and Ice. That way, all 3 classes (that has Ultimates), will be satisfied. And Night Lords will probably have more maps/places to train at, and people will complain less (because as humans, we always and will complain...).

EDIT: To clarify on what I'm talking about, it's those walking FAT trees monsters, plus the FAT tree boss.