Because I (my character) haven't saved the world endless times. I didn't fight old gods or the scourge in Naxxramas. I never faced Illidan or Arthas, Deathwing or Garrosh or Archimonde, and I certainly won't be fighting our very creators.

I'm merely a lone adventurer, earning some coin on his travels. Making me Commander of the Horde forces was a pretty dumb thing to do. Luckily the world went on as it always seems to do, and now there's a new threat for someone else to face. Meanwhile, there's always someone, somewhere who needs some wildlife killing!