You forgot bugged Dragon Soul, no ghost mounts, nearly every dungeon is bugged, bosses are evoiding your attacks, pets pull mob groups randomly in rhot dungeons, no dungeon finder, no raid finder, no Nefarian, wl pets are doing 30k dps in raids, beth in firelands instantly wipes the group ( if you dont logout before encounter starts and have a suicider to start the bossfight), ragnaros hc half scripted, Spriest does no dmg, Boomkin does no dmg, Prot warrior is bugged, not all arenas are open, not alle battlegrounds are open.....
so your asking why customers of the servers are leaving?