I would love to be able to adventure in Skyrim with my friends and I think the main series could coexist with an MMO just fine. I don't get where the ridiculous aversion to multiplayer comes from.
MMORPGS:
-uncreative
-unoriginal
-horrible, boring questing system
-annoying player characters swarming around
-identical to one another most often
-annoying trolls/hackers/idiots
-lag
-lag
-more lag
-downtimes
-WoW
-No actual impact/purpose in game (4,000,000 people do the same quest?)
-Less versatility
-Much much more