Having worked on a FPS MMO, I can't agree with this enough. People always complained it didn't look real enough. I always wanted to ask them if would mind buying 1,000 video cards up front and then wait 10 years buying 1000 new ones every year until I got it right. I figured by then I could retire and duck the problem. Reality is ridiculously hard to do right. Now try doing it over the internet with a half second ping time and you realize that not only reality bites, but physics bites harder.
While WoW looks the way it does partly because of it's 10 year old origins, it's artwork also communicates to the player: "It's just a game". And once you're far enough away from an imitation of reality, the brain stops trying to fit it into it's model of the world and complaining when it can't.
