Originally Posted by
Jokubas
It's more spoilery than you might realize.
Spoiler Elaboration Below
It's not exactly the same thing. Sargeras and Aggramar were the only Titans to know what evil was when he first made his move. Sargeras almost certainly made the right choice in destroying that first planet. The other Titans disagreed because they didn't even know what a demon was, let alone a Void Lord. That's a bit similar to Arthas in Stratholme when it comes to the fact that those people were definitely doomed.
The real difference is when it comes to Azeroth. Azeroth has shown to have quite a good chance at winning the battle against the Old Gods and the Void, and Sargeras doesn't seem to care. By the time Arthas did anything that evil, his soul was stolen, he was essentially mind controlled, and he wasn't trying to justify it. Sargeras just plain gave up hope.
It's a funny post though. ;P