So what? theres high orcs and mermans everywhere, they're easier to kill and give more xp still, but deviaces give uh... nothing.
I get more xp from the 3 mermans spawning there than the deviaces

Theres also lots of dullahans and kasas, they also give lots of xp, so what?
And the normal number of deviaces is 3, if theres like 25 is because they increased their number, but is pointless to hunt them anyways except for quest
Edit: I'm not trying to prove anything, nor ask for the xp to be back to normal, I'm just curious why reduce the xp by around 1/4 and increase their number, if then no one will hunt them? (assuming its like this before quest)