He knows he'll die soon and he is afraid that she'll grieve or be too sad so he tries to make her hate him so that she could be happy even after he is dead.... it may seem stupid but he is scared just as much as she is , it's true that his choice is bad but it is understandable!
Like bro, i know what you mean but that's still so frustrating becaude he's too weak in his resolve, he's just being a bit cold, that's not going to make her hate him, even in her previous life, she didn't really hate him, she just thought he hated her or would reject her.
If i was the father and i thought making her hate me was a good idea, i would buy her a pet and kill it in front of her, make her think that every little misfortune was because of me, make her wish i was never alive.
It's only when you truly hate someone like that that you can be happy at someone's death, otherwise she's just going to be sad, she's not heartless, death isn't something to be happy about in general.
It's annoying that there's litteraly no reason why he acts like that other than a dumb pretext to advance the plot. Like if it was something like "oh but you can only use the power of the branch if you hate your predecessor" it would be interesting to see the dad try to make her hate him but still fail because he loves him.
Pussy father, scared of saying i love you and im worried?
Pussy father.