I think you forgot something. Unless a person is a very hardcore gamer, he/she plays game for fun, entertainment and not looking for something meaningful in life or something deeper or whatever. Isn't it the root of what gamming is all about in the first place? I know fun is a subjective word. But the key here is to provide fun for as many people as possible. And Blizzard did just that. WoW does not strike for anything deeper, better or more meaningful, but it provides a lot of entertainment value to a lot of people.
That's great. However, its success has had the unwelcomed side-effect of making a large number of game developers and more specifically their publishers believe that all MMOs should strive for brain-dead fun and depth be damned in ANY circumstance. Not everyone wants to play a game where they can scoop out their brain and smile droolingly at a screen and make the same progress and have the same success as anyone else. If EVERYONE wanted this kind of gameplay...then EVE Online wouldn't have been able to rise from nothing to a successful MMO.
Making the game so that even 9 years old can play, is that bad? Hell no, if they made it so only 9 years old can enjoy than yeah, it's bad, but they made it so a lot of adult can enjoy it too. If they make it so 3 years old can play and we adult can still enjoy the game then more power to them.
There are a staggering number of adults walking around out there who exercise just about the same general mental capacity(and sometimes less) than your average 9 year old. It just doesn't bother society as much these days. They get elected to President.
This is where you are wrong. track record and marketing moves can only get you so far. Look at AoC, the marketing hype went through the roof. But sadly, Funcom only stop at marketing. Look at the sale chart for North America, all 3 WoW titles still in the top 10 after 4 years. Where did it snowball to? After 4 years, people are still buying the original version like that, they must have done something RIGHT with the game.
Show me what title it was that Funcom EVER produced that ever rivaled anything that Blizzard did. See this right here shows that all you're doing is reacting out of emotion. When WoW was announced, Blizzard had under its belt Starcraft and Broodwar(insanely successful and played up to this day), Diablo, Diablo 2 and their expansions(again still played and in the minds of gamers everywhere). The Warcraft RTS series and its expansions(again hugely successful on a grand scale). You think Blizzard only had a handful of fans when WoW launched that were going to buy the game? You're deluded.
Blizzard's marketing is renowned in gaming circles. They understand what it means to build a craving for a game in their fans like few other gaming companies. And they are damn good at it. I've heard other game developers say the same thing about them so I'm not pulling this out of my butt.
Oh lest I forget, the other factor that drives the nail home in the coffin. It runs on just about any piece of junk PC out there. Another Blizzard trademark.
Add that stuff to the polish that ALL Blizzard games get shipped with and then factor in that online gaming was only JUST starting to really become mainstream and voila. Instant freak success...as possibly only Blizzard could ever deliver it. Funcom didn't 'stop at marketing', they used the Conan IP to promote a game that wasn't ready for launch and wasn't polished. That is a recipe for failure for ANY game.