I don't like Sylvanas. That's not to say she's not compelling - her character is fantastically written, and I don't think that anything she's done is out of line with her character, Teldrassil included. She's always been - for lack of a better word - an extremist. She's out to do what's best for the Forsaken (Horde comes secondary to her, I think), and she'll crush who and what she needs to in order to do that. She wanted to make more Val'kyr in Legion, she's always been trigger-happy when it comes to using Blight, which everyone else in the Horde opposed. She's a ruthless leader, and I don't think anything's changed in that regard at all.
For me I have always disliked Sylvanas and I feel like if she was not a fan favorite we would have already fought her in the past, BUT the outrage would be insane based on the community response about her burning down the tree. Her doing that turned the Horde into something I didn't really want to be a part of. For me, the Horde was and has always been about honor and the outcast faction, that's why I liked it all those years ago.