I agree, I’m a little sad at how negatively some commentators are responding. I think the author did a great job showing how one person can recover from abuse and find joy in reclaiming their sexuality and turning it back into something healthy (if not perfect), like the ML, while someone else who went through the same thing but never even started to heal from their trauma can end up just furthering a cycle of repression, violence and abuse, irreparably harming everyone around them, like the antagonist. They’re foils. His story is tragic, but the author isn’t saying he’s justified.
i've noticed that many mangago users don't understand nuance in storytelling. they apply moral values without consideration to context. i suspect they're very young or have read few novels, which concerns me either way...
on another note, i love the way you have described this story in your comment. it's spot on, and what i was trying to convey—but my phrasing was far clunkier.

wow... the author does an incredible job at sensitively and meaningfully depicting horribly abusive situations... i love how she's illustrating the impact of sexual abuse from multiple perspectives with entirely different outcomes