Welcome to one of my favourite rants...the continued use of NPC's in online games. World of Warcraft is one of those games where people pay 8.99 a month to play a single player game with a chat option. In inclusion on NPC's in an online game is baffling, especially when they encroach on the story.
Now, I do not suggest that the NPC should be completely removed, but changing it's role in an environment could be of benefit. Why should an NPC tell you to collect 40 rolls on fabric from the corpses of dead mammoths, so they can make a pair of trousers for themselves? Of course, you, as a player never see this benefit.
I would love to see NPC's employed by players to add service to towns. So a twon could primerely be inhabited by players, but NPC's are employed to act as shopkeepers, auctioneers or even sent out to run trade routes on the seven seas. Quests can still be handled by npc's, but if someone is employing them, it would seem more important to keep them happy and in shoes.
And, of course if another player starts killing your NPC's, you should have the opportunity to revenge them for increased experience.
Wurm Online (www.wurmonline.com) has a basic version of this, NPC's can be employed to be merchants. Maybe it's time for others to follow suite?