Baine is shit but he's the preferable choice in an MMO RPG game that was initially designed around "create your own adventure" with a very subtle narrative that didn't hijack the entire PVE play experience. I wouldn't take Baine over Sylvanas because he's a better character, I'd take him over her because he would never be put in a role where the game's narrative revolves around him like Sylvanas is, and the bitch might not even be the main villain.