So we all cheered Daenrys when she fried the loot train in season 6, killing hundreds of innocent caravan folks. And then mercilessly executed all the prisoners of war. Because well, f*** Lannisters. Jon Snow stood there watched her do it as an ally and later a lover. And we all cheered.
And yet, Sylvanas burns down a freaking tree, which i can bet most players haven't visited in like 5 yrs, and suddenly she is all bad? It was strategically needed. Where was the NEs when she was turned into a Banshee by the Lich King while defending her people?
Where was Anduin and Greymane? They can make portals to send players from Stormwind to Darnassus to help defend. Yet they are too busy to defend their ally? They can send a Hearthstone to help Tyrande teleport out with Malfurion. Greymane can port himself there and save his wife from the carnage. Yet, he doesnt bother to stick around and see what he can do to help the remaining NEs escape.
So why all the QQ over Sylvanas? This is War. She did what she had to.