They wasted so much time developing Garrosh just to do a 180° and made him suddenly crazy to justify the stupid ass WoD expansion.
Garrosh made a difference between the alliance and the horde instead of making the horde a red coloured misunderstood alliance that is also good.
If I was Blizz I would have done things differently.
The horde is loyal to Garry. Each race in the horde seeks something and they help eachother. Orcs and Tauren seek a more prosperous place to live, forsaken seek a cure, elves new sources of power, trolls to reclaim their land, goblin to make money.
Instead of Garry being pseudo Hitler, he unites the horde to get each goal in an aggressive way.
In contrast, the alliance is a defensive force instead of an aggressive one.
Basically the idea would have been to make the factions more different to create more interesting scenarios.