That he kills pandaren and ruins their shitty island paradise of crazy reclusive stagnant dogmatists doesn't make him a bad guy in my book. It makes him a good guy. If the horde voted for leaders, and he ran on the platform that he promised to impale all the pandaren he could find ON THE SPIRES OF ORGRIMMAR (!!!), I'd vote for him, and I'd tell all my friends to vote for him too! If he also promised to personally kill all the non-horde orphans he could find, by strangling them to death with his own bare hands, I would've lobbied for him!
What they're doing to really make him into a retarded caricature is make him an obvious, blatant racist who hates every non-orc irrationally and excludes everyone from his TRUE HORDE based essentially on them not being orcs. If you had taken the 5.4 launch trailer and replaced all his "I"s with "we"s, and made him talk about the "HORDE" instead of the "TRUE HORDE", and made his goal slightly less absurd (ie. made him have one), he'd be an awesome leader for the horde. But they just made him hate the horde and decide to attack it because uh he's a bad guy I guess, even though it makes absolutely no sense for him to be doing any of the things that he's doing. And now his plan is to sit in orgrimmar while the armies of the world come to kill him? Because he's so full of hatred? Yeah... that makes sense.
If he was just *slightly* less of a rampaging lunatic he'd be a perfect horde leader.
Of course, they had to make him into this super-moron, because otherwise people would like him too much for all the things he's doing. It's so lacking in subtlety it's not even funny.