The song starts off:
"The white man came, across the sea. He brought us pain and misery."
Well this could be from the point of view of an Orc (like Thrall)...literally the Humans come from Stormwind across the Sea to near Orgimmar and bring misery to any PVP over there :P
"He killed our tribes, he killed our creed. He took our game for his own need."
So, killing little Orcish outposts and taking their game could be either something for a quest or a Hunter taking one of the beasts and taming it to use against the Orcs....
I'll have a longer analysis about this later on but thats just the start of it. :)
I'm a nerd!