I feel like the argument of, "This is Blizzard bad writing" is a boring one. If there is a situation where you can rectify or fix the writing please do it! But I also think its fun to discuss what they're going for too.
-
I donno I've heard actual devs talk about the Garrosh angle being a miscommunication between the devs more than players.
I heard during MoP's blizzcon when they were talking about what Garrosh was doing to everyone that people started to leave and Chris jumped in saying you'd get to kill Garrosh as the end boss. So it seems uncertain. Garrosh seemed like he was gonna become a good Warchief.