Nice way to leave out that the "Horde" that killed Cenarius were corrupted by Mannoroth's blood.....
Let's not go into this again. At that point in the campaign Hellscream willingly drank the blood for the second time.
Didn't say he didn't...but the entire Horde did NOT willingly drink, just the band that Grom had control of.
As for what's going on now, Garrosh is Warchief.....need I say more on that? Not to mention you precious Alliance having a good part of your druids going to Ragnaros and becoming Flame Druids.....yeah I didn't see any Trolls or Tauren in their lot.