Eh, I don't mind having a Fields of Valor type situation where you can gain XP faster by targeting certain types of monsters (assuring that you actually travel around the area and fight different types of monsters rather than finding the best place to grind out Coblyns). I don't want any of that sh*t in my questing, though. To me, if you can't throw in a bit of original story and scenario, don't @#%^ing bother calling it a quest.
MMOs are notoriously terrible about this. It'd be one thing if they made even the most minimal effort, say by imposing a time limit on the Kill 10 X quest, but it's usually less of a quest and more of a "Hey, why don't you go XP on spiders for a while?"
Yes! Yes, exactly! It's the fact that these MMO "quests" are too bare-bones to be called such, and because they become stale incredibly quickly, that their presence is so annoying.
Give simple, grinding-type content without a story for exp. purposes, and give interesting narratives to quests. If you give a narrative with every little task, then we just get 200 forgettable walls of text that involve poor excuses to hack at monsters spawning right next to us. It's a poor design, it's a poor story and, worst of all, it's not even fun to play through!