It's very frustrating to continuously run into aspects of WoD that feel sloppy, untested, incomplete and poorly implemented.
One example that really irritates me is the Bodyguard system. A lot of players are using their Bodyguards again in Tanaan. They can be very helpful for squishy classes like Shadow Priest, especially if they are not highly geared.
Bodyguards are a great concept. But their design is an embarrassment. You can't control them at all, can't tell them to start fighting, or stop fighting, or move where you want. And they have this massive click zone that triggers their basic dialog box that is constantly popping up when you just want to loot.
I'm sure the flaws in the Bodyguards were pointed out early in beta. Yet Blizzard went with the current sloppy and incomplete implementation.
My latest frustration is my Shipyard where all my ships are Epic and don't need more XP yet every single mission on the map is an XP mission. Guess I have nothing to do! Even the dumbest phone app knows that they have to keep you playing.
I'm sure others here could point out dozens more examples of the WoD motto, "Sloppy and Incomplete".