She was screwed over in her first death, for sure. Her actions up to the death of Arthas are at worst morally dubious antiheroic. But her actions after that were utterly black-hearted evil.
Kael'thas started out fighting for his people before ultimately selling them out for power to the Burning Legion, and he got Revendreth. But that's because, with his pride beaten out of him, he might actually admit he was wrong and use his power for good again.
When Sylvanas watched Teldrassil burn, in those dead eyes there was a faint smile. That is Sylvanas Windrunner, as she is now.
This was her choice that would've had me consider Revendreth.
Maw.