What is missing for me is guild raiding and comradery. In previous expansions there was not option for LFR and guilds were not optional for those wishing to raid. But now you have this uber elitist attitude where it’s almost a status symbol just to be in a good raiding guild. You can’t raid above the LFR level unless you’re the best of the best or you have good social connections in game.
In my opinion, this is the biggest problem currently in retail WoW. I can’t answer for you though in regards to your issue with the game.