WoW sold so many copies/has so many subscribers because it appeals to the "outsiders" mostly.
I still remember how I first was happy when gaming started to move from obscurity to mainstream, but oh boy, do I regret it now...
I really really want people to enjoy their games, I'm happy they can like wow, but then it strikes me, again, how this influences us all.
I've been playing videogames since approximately 1985, I tried to get earlier games on different platforms for my collection too (I still have some 70ties TV-Games) and of course I tried WoW. How people can play this without feeling mindnumbingly bored is TOTALLY beyond me. You've seen all the game can offer in such a short amount of time (because the patterns are so freaking obvious), and there is so little you can do.
If I think back to ultima online, even after they split the world into trammel and felucca, that was a game in which you could actually do stuff. Other than pointless grinding, that is.
Or something else is Guild Wars. I don't know how the game is today, but back then, when wow was new, GW was new, too. The games, albeit pretty different in their design, got compared pretty often. All the things that get advertised as the stuff thats the actual interesting stuff in wow... well, GW did it better.
The little 8 skill restriction that your characters have, those actually made the game interesting. Also it took you only a day to build a proper character that could do everything in game.