It was directly mentioned by the spirit lady when he was mildly distressed about being okay with killing. Allen's view with the guinea pigs is just his biased telling and how he justifies in his own mind.
The action of disowning her is not what I am calling terrible parenting. More specifically its the way in which he did so. Had he been a mildly compassionate human being or half decent parent he would go to his daughter and say "Hey look I love you and value you a lot but the rules are how they...
Terrible parenting meets angsty teen, tragic backstory ensues
Can't say I hate it altogether just like...disappointed after how it opened with the first 5 chapters and then has kinda just kept existing since that point
Edit since first page:
The action of disowning her is not what I am calling...