Yrel's Lightforged forcing the orcs into the Light - BAD!
Undead killing the living only to turn them into the same state they supposedly hate, not only making their first death pointless, but also forcing them into choosing between being an abberation or dying a second time - GOOD
Sometimes I wonder what was even the point of Northrend campaign. Forsaken are what the Scourge was before Wotlk - a thread to the world, but not full on aggression towards all of the living. And the living only decided to fight back after Lich King's invasions. No lessons learned though, since they allow another bomb to tick.