Wows peak was in bc/wotlk it's been in decline since cata release
I tried a few dungeons recently in the pandaria expac and the pve has been dumbed down so much
It's like a different game
The Pvp is still fun though
Blizzard is just not the same company they were. Like many they are victims of their own success and got too big for their own good. As someone who has been playing games since the 80s it seems to be an all too familiar cycle. Eventually once a company gets very large and becomes publicly traded, profits are emphasized over game content. This leads to the eventual "dumbing down" of everything in an attempt to appeal to absolutely everyone.
Really, WoW killed Blizzard (at least from a quality stand point). It just completely changed the company forever. Diablo 3 is probably the biggest disappointment I've ever experienced in regards to a video game. I doubt any of their future releases will ever be up to the same standards as anything they did pre-WoW.