
That in order to make your audience ROOT for a flawed , messed up, toxic character, you have to make sure he isn't absolutely IRREDEEMABLE!!!
Stuff like Cheating, domestic violence, killing family members, completely destroys the ML's image and you're better off just killing him atp.
Confinement, drugging, rape, sexual abuse, apathy, betrayal of trust etc are themes that with the right character development are often forgiven by readers (not that it's right whatsoever, but you come to expect them from stories like these).
But this one?! Moyoung got his memories back first alongwith his present memories and STILL didn't think he did anything wrong. Like Mooyoung can never come back from all that shit bro.