I don't really care who is at the top as long as they represent the horde's people and it's values.
The horde has progressed far beyond a rampaging rabble driven by demonic fury.
Don't forget that there is no suggestion that this would lead to any kind of deal with the alliance. The leader would still be opposed to the alliance.
I believe that of the 2 factions in WoW the horde is the one more likely to judge a person by the content of their character and nothing else. Sure, there are nutjobs in the horde, but by the end of the expansion there should be a significant reduction in that kind of thing.
As an aside, it's worth noting that the majority of major faction leaders throughout WoW have been pretty moderate with only a few exceptions (during the timeline of WoW, not beforehand during the RTS storylines). This will be quite deliberate, as creating a leader with political views that are too extreme will either alienate players (even disregarding the rest of his character Garrosh's extremism is a huge part of why people dislike him) or potentially attract the types of people that the media has a field day with when they find out that they play WoW. I just feel that as a whole the horde has more progressive politics, whilst the alliance sticks to old values for far longer.