To be fair, Azshara and the Old Gods also picked that time to attack. His Scroll-empowered orcs would probably have been able to handle one front on their own, but with all the universe's hostile powers, and the Alliance and Horde both wiped off the face of the map (and, one would assume, whatever coalition the neutral factions brought to bear also wiped out thanks to the functionally-immortal orcs), Azeroth was toast.
Be seeing you guys on Bloodsail Buccaneers NA!
To be fair, that scroll is a pandaren artifact, so naturaly it is full of shit.