I really don't understand some of you people.
*Rudeus is a socially incompetent person with decades of maladjustment, being used as a pawn by a powerful entity in a game he has no chance of surviving without either blind luck or the mercy of his enemies, who has had approximately 8(ish?) years of a half-decent life and family before being forced to fight for his life day in day out for multiple years (IIRC), then coming home to a broken family where none of the adults were overly admirable in the first place, and finally being forced into political bullshit concerning his student/friend without warning. All while suffering through puberty with no real guidance.
*Eris is suffering everything that Rudeus is, except that she replaces the old memories with: watching her teacher/friend get murdered right in front of her eyes, finding out that all members of her family are either dead by murder or effectively enslaved, coming back to find someone she trusted advocating that she get married to someone she knows is a backstabbing jackass, and having exactly one ally to rely on-the aforementioned teacher/friend that she watched die.
I understand that you find elements of the story distasteful, but this undying hatred for characters who have suffered more in their childhood (or second childhood as the case may be) than the vast majority of people can even comprehend in their lives is just completely fucking silly. Seriously, you're over-reacting like Orsted here.