The complaints mostly are not about the quests. The complaints are coming from people that view quests not so much as a play experience but a way to farm loot. Their complaints are almost entirely about loot (with a few complaints about the size of the wilderness and backtracking in one of the quests).
Heh? There are plenty of complaints about the quests.
There's a quest, I am not joking: crest:slot, crest,crest,crest:slot,slot,slot, crest:slot, crest:slot, finish. Oh, optional? Wait for it, crest: slot.
Another quest: insert 3 crests. Insert 3rd crest: quest object: insert 2 crests.
The hallways are drab, the enemies mostly just dot you.
I kid you not - nearly 20 levels ago I was slaying HORDES of devils and orthons in the plains of shavarath in a new invasion and sins of attrition. Sins I could run through and literally just mad-gibs watch orthons explode all around me.
Now a GOD like level of power later, I am murdering flame skeletons and worms. I fight a Lich who somehow has less power than the liches that are wandering around in the Orchard SLAYER zone.
The quests are fine for a level 13 add on pack, massive fail for end game, in my opinion.