Here's something I don't understand:
Elves live for tens of thousands of years.
Every single last Blood Elf featured in the story has been alive for thousands of years.
The invasion of Quel'Thalas happened thirty years ago canonically.
In thirty years, the giant scar the undead left in their wake has healed.
Thirty years is less than 1% of the lifetime of a Blood Elf.
Why do they care about the scar so much?
Why don't they see it as a temporary thing that will soon come to pass?
