I'm just going to throw this in here:
First of all, no, I don't think they'd accept human as warchief. It's just not realistic in the current state of things.
If I'd have to think of the best option for Warchief of the Horde it'd have to be Sylvanas.
It is inevitable, and I bet my (character's) life on it and see it as 100% guaranteed that one day Alliance and Horde will JOIN as a coalition in order to fight something which would otherwise destroy us all. I think we can agree that's pretty much inevitable.
In that situation they'd pretty much have no choice but to sometimes obey orders from human in tide of battle, but that's as far as it goes I imagine.
"I hated hating Garrosh before it was cool."
FOR THE HORDE!!!
It'd be possible, but we'd have to be talking about one scary bastard here, a wild-beast-man-of-the-hills with a thousand screaming hairy horsemen at his back. The sort of fellow, in short, who would be rolling siege towers up to the gates of civilization anyway. Anyone from the kingdom of Stormwind, or Gilneas, or Dalaran, or just about any of the known human kingdoms would be right out. Inside information or not.
Even if a human were to gain a high position in the Horde they would still be looked down upon by the more patriotic factions similar to the way the Kor'kron in UC speak to undead players.
You're putting too much trust in 'building their way up' and ignoring the racial prejudice. The Horde will NEVER trust a human enough to lead them, just as the Night Elves would never trust a demon. The human could earn enough trust to be accepted, and possibly even revered by many. But there will always, ALWAYS be enough prejudice against said human to prevent him from becoming Warchief.
Are you asking me to stop punting gnomes?
Same answer different question. NEVER!
Only if we kill him/her and they come back as a Forsaken. Other than that nooooooooooooooo!
I'm a Forsaken. I kill firstborns while their mamas watch. I turn cities into salt. I even, when I feel like it, rip the souls from little girls, and from now till kingdom come, the only thing you can count on in your existence is never understanding why.
Humans are too weak. alot less strength than an average orc and they are less honorable.
and their battlecry's are quiet. Only humans that are as powerful in physical mass are such as lothar, varian and people like uther. But even they have alot less strength than an equal ranked orc.
Lothar wasnt as powerful as Doomhammer. Maybe as good fighter but orcs are all about brutal strength, some are shamans and warlocks but even they are more physically powerful than a human mage or a priest.
And human are bound to fear alot easier than orcs. And they are easier to influence because they dont keep honor as valuable as the orcs.
Besides if a human ever wanted to become a warchief he would have to slay the former one in a honorable duel. This aint necromangi in which they could just kill the leader and own all his belongings and power.
And there are many more moral reasons why a human can never be warchief of the horde. :P
---------- Post added 2013-03-05 at 09:37 PM ----------
To compare a human who's liked be everyone to a demon who's... Well; nót... Would be odd, indeed.
Basically: Would a human warchief be possible? Sure.
But let's follow a few steps of logic, here:
There's millions of Hordies.
There's only a very small amount of human hordies. As in: Not enough to appear in-game at all ever. Well; not the living ones, anyway.
Then there's only a very few amount of people who are exceptional enough to even be part of the 'upper crew.' The mercenaries/adventurers (us) and the major lore characters.
A live human is not among the upper crew of the Horde.
Ergo: While the idea of a human warchief is not impossible per sé, it is so incredibly unlikely as to be completely negligible.
They probably don't even trust their own allies enough to let one of them become the Warchief, let alone a Human.
That's exactly my point. The orcs value strength, perhaps above all else. After all, sometimes an orc will just grunt, "Stregth.", at you as a farewell. They pwned Stormwind, pwned it with several unfair advantages, but pwned it none the less. I imagine that the orcs could think of nothing worse than to be ruled by a subject of the kingdom they levelled when they first invaded Azeroth. They might show Lothar some respect but considering he's been in the ground for a couple of decades now, that doesn't count for much.
I think the orcs would be less bothered by being ruled over by a human from, say, Lordaeron, seeing as, with aces like the paladins of the Silver Hand, the rangers of Quel'Thalas and the Wildhammer gryphon riders up their sleeve, they beat the Doomhammer's Horde by quite a margin. But, as fate would have it, most of the humans of Lordaeron are Forsaken now and they answer (reluctantly) to the Warchief (for now anyway).
The main population of humans lies in Stormwind now and the orcs would not accept being ruled over by a defeated opponent.