Skoll Shorties

Plenty of Orcs committed genocide in a same sense as Garrosh. So there's definitely room for some redemption. Obviously, I can't see him being "redeemed" in the eyes of most of the Alliance but the Horde is a possibility - maybe.

His thinly veiled allusions to what he considered racial purity put him over the edge in my book. That and him screaming "I will drown this world in a river of blood". Puts him past redeeming.

The big difference I can draw between a character like Sylvanas and Garrosh was that Garrosh did everything for his people in his own twisted way. Sylvanas is doing everything for herself.

I don't think one is better than the other. Rampant racially driven genocide is rampant racially driven genocide. Sylvanas is still the worst and a badly realised character(after Wrath, anyway), but Garrosh doesn't deserve redemption. He's a monster on par with Gul'dan.

I think Gul'dan and Sylvanas are up there but Garrosh's main motivations were driven to ensure his people had a future. Again he definitely went too far with it and there are certain things he'll never answer for BUT I do think there is room for some kind of redemption for him.

Racially driven genocide and obsession with blood purity put a character squarely in the "not redeemable" category.

I don't really understand how "Blatant jingoism and racial extermination can be forgiven under circumstances as long as it was in the name of patriotism" is a take you can go with, but sure.