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want an MMO with no NPCs at all, where everything that gets done, and made, and sold, is handled by people.
It has been done, just look at second life.
I think though that the hardest part of having an mmorpg without trivial quests and repetitive leveling of near useless stats (ie. a mining stat) is that without them, it leaves little to do. Without such meaningless activities you are really only left with walking around and leveling, which can get really boring, really fast.
I think this however would be fine if the fighting sytems were already interesting. I think part of the problem is that most MMORPG's today have a very weak character model. There is always a tank, a damage dealer, a healer, a buffer, and some solo type (think beastmaster) characters. I think this is fine too, but there are almost always only a few builds for the optimum tank, or damage dealer. When your playing near end-game, a cleric type character will always have the same armor (or is currently working to acquire them), will usually have the same or similar spell lists, and will be one of a few races. This is very contrary to D&D where different character Races/Builds are encouraged and really add to the feeling that you are an individual in a Multiplayer World.
Another reason i believe that the fighting systems are so weak is that most modern MMORPG's are stuck to the idea that RPG combat should always be about picking a command from a list in an appropriate order. Many single player RPG's ingeniously move away from this model and really make the game way more interesting. Super Mario RPG allows for a character to increase damage by pressing a button within a small window. Final Fantasy X-2 allows damage bonuses by having different characters attack near simutaneously. Even old school hack and slash requires you to at least press a button if anything is to be done.
As for people that think that players in MMO's should be rewarded for skill, rather than time spent in front of a computer screen, you should really look at puzzle pirates. It's an MMO puzzling game that has really great clones of Bust-A-Move and Super Puzzle fighter, as well as 16 other puzzles that are all really fun. They are even currently having contest that allows players to design the next crafting puzzles.