"Doing fine" is a euphemism from my point of view. Blizzard had over 10 million subs at WoD's launch. If you lose around 40% of you playerbase in just over half a year, you sure as hell aren't "doing fine".

While the new zones and leveling 90-100 was quite a treat, especially compared to older expansions, there was barely an end-game, which is what the playerbase truly thrives off. 1 raid on launch (in the past we've had 3-5), plus an incredibly broken open world pvp battleground (queues @ 2+ hours for some people). We didn't see our second raid tier for 2 months. 3 months later they brought in a new area that was supposed to be included in launch and our 3rd and final raid tier, in which they just decided "What the hell, lets throw one of the most powerful beings in the universe lore-wise in as the last boss without rhyme, reason, or explanation". I'm not even kidding, he just pops out of nowhere and you defeat him without really knowing why he was supposed to be there in the first place. What started out as a great expansion hit a wall bigger than Game of Thrones' once you actually started endgame. Remember those really cool Warlords trailers? Yeah, none of those guys were final raid bosses, and some of them, like the promised end of expansion boss; Grommash, weren't even raid bosses at all. I won't even get into the "facebook-ification" of WoW through the Garrisons.

As a WoW player on and off over the years since beta, I've got to say WoD has been an absolute travesty, zooming right past Cataclysm for king of the shit-hill. Of course all you have to do is say "sorry, we fucked up", and put out another expansion and it's like nothing ever happened. Watch as it bounces back up to 10mil just before the next expansion hits.

There's a lot of hype coming about the new expansion as there are rumours circling that WoD's development got capped at the knees to focus on the upcoming expansion's development. If that's true, I find it incredibly poor of them to focus on something coming 5 years down the road instead of what's right in front of them.