It's all about the enemies you are fighting. They have you fighting enemies with high yield XP rewards, but they nerf the enemies so they aren't so tough that they kill you.
So, for example, in the Nautiloid, you should fight manes and dretches, not imps. Dretches and manes are level 1 fiends. Imps are supposed to be tougher and give you more XP when you kill them.
It's that way with everything in EA. You get lots of XP for everything so you don't really enjoy each level. You rush through them so you hardly experience them or the monsters you should fight at those levels.
