The Death Knight starting zone is more interesting than the demon hunter one.
The Scarlet Crusade and Brotherhood of the Light are more interesting than the Argent Dawn, Crusade, or the Silver Hand.
Arthas is arguably the most popular and interesting character in all of WoW's lore.
Taking the concept of a moral paragon adventurer and flipping it on its head is interesting. Robbing a group of everything that made them unique so they're exactly the same as the concept they were originally intended to be a foil to is not interesting.
I could forgive it if not for the fact that Blizzard said Liadrin forbids the Blood Knights from simply siphoning Light from the Sunwell, which means the only way for them to do what they do is to be good little long-eared human paladins. Blood Knight has no meaning. They're just paladins. And they're doing the same to the Sunwalkers who are druids who wear plate and do mostly sun magic, having Aponi Brightmane in the paladin order hall being like "wow I'm learning so much about the Light, I wanna learn more." They seem incapable of maintaining diversity in their game's world and are hell-bent on homogenizing everything into one grey blob with no distinct characteristics whatsoever.
If you want to play a good happy funtime good guy, play a human paladin. They didn't have to take the Blood Knights away from us. Make Liadrin that person if you must, but they shouldn't have said she forbids anyone from doing things the old way.