you worded it so perfectly like hell ofc it doesn't excuse what they did but it gives you an insight on how and why they turned out that way ! cause really, a person's environment affect them big time—where would he learn to be normal when everyone around him is a psycho (?) theres this famous character who has a perfect life and a loving brother (from a very famous story) really has no reason to be the way he is but hes j pure fucking evil for no reason at all and people still ate that up.
Tbf, that last part you described CAN happen in the very rare cases of actual psychopaths who experience even a slight childhood neglect. But those are honestly the tiny exception.
Everyone else is a product of the behaviors they experienced and were modelled to them as kids, combined with their genetics to a smaller degree.
And like you both said, these background stories act as an explanation, a deeper view into a character and what they'd been through, not as a justification or excuse. Readers don't owe to suddenly turn our views around completely just because of it, the actions of a fully grown man as he is today are still his responsibility.
Admittedly, there ARE occasions where authors do intend to elicit specific favorable views and feelings towards a cruel character and have them be redeemed, in the way they portray those past events and how they tie them into the present or how they have other characters react upon finding out. That's to say, when it doesn't feel organic, but forced.
I'll be honest that I'm not a big fan of this author's approach exactly because the whole rape incident went away literally with a slap of the wrist (ok, one slap on the face), so I don't trust them to do any redemption organically, but at least I appreciate reading of Lorenzo's past.

i think we as readers can be too quick to call a backstory a sob story, and sometimes an characters past explained can feel sloppy and like a nonverbal apology. But a bad person doesn’t just appear, they’re a product of generations of trauma, enabling, and lack of moral guidance in their developmental years. I actually think Lorenzo’s father getting irrational and angry, even hurting Lorenzo might be a perfect portrayal that though he loves his child, tries to look out for him, he’s still a product of his own father’s parenting. It can feel annoying when you have to hear how miserable a bad person’s life is, and in no way shape or form would that ever be an apology or repentance, but i think a character born to be *just and conveniently* evil is an easy route to avoid layers and depth to developing a character. Anyways that’s my two cents or maybe it’s just nonsense.