That guy got his own kid killed.Sunwalker Dezco.
He has: a well-documented history of service through the expac, has formed the best relations between the Horde and the native Pandaren of all the Horde characters, he's seen Garrosh's madness and tyranny first-hand, the player base has an emotional connection to him after his wife's death, AND he has a really good rapport with Anduin Wyrnn, the prophesied leader of The Army of the Light and Prince of Stormwind. If anyone is able to bridge the gap between Horde and Alliance to defeat the Legion, it'd be these two. Plus, we know that some sort of great vision lead his wife and their party to Pandaria in the first place.
(Oooph, upon thinking about it, how much of a kick in the guts is it for Dezco to walk into the Vale, see that place and KNOW it was the subject of his wife's vision and KNOWING that those waters could've saved her life? Then spend the rest of the expac watching it be torn apart under Garrosh's idiocy. Ouch.)