can anyone pls remind me why he doesnt like the previous emperor?

It’s kinda like a dad being too hard on his kid. The current emperor used to be a useless prince, so the late emperor looked down on him. That’s why now he doesn’t really like the second prince, cause his looks, personality, and smarts all remind him of the previous emperor

And the story is repeating itself, he looks down on the first prince because he is incompetent... Ironical isn't it ? The physical ressemblance is even more symbolic here