The obvious and ever-ignored difference by disingenuous posters is that the draenei took no part in the crimes of the Man’ari whereas the orcs of Thrall’s Horde were the perpetrators of the several genocides undertaken by Blackhand and Doomhammer’s Horde.
Alliance race? Collective guilt all the way. Horde race? Believe it or not, no guilt for anyone. And then we get forum posters whinging about Blizzard’s hesitancy to ever show the Alliance in a less than shining light.