I was always impressed by the devs of Final Fantasy Online and ESO, and how these games at launch received garbage reviews and were doomed to be just another 2 failed MMOs.
Then the devs reviewed every single aspect of the game, in the case of FFO I think they even shut it down for a whole year, re-launched the games, and now they are praised in the top 3 / top 5 of MMOs on the market.
Blizzard did the same thing with Diablo 3 with the Reaper of Souls expansion and literally every patch that launched after. Whether you love or hate D3's main story or art style, you cannot deny it is a beast of an ARPG compared to what it launched as, and ROS' story was very good as well.
Whatever issues WoW has, they could be fixed, if there was a will for it, WoW makes more money per month than most MMOs do in a year probably.