Responses
They were two profoundly broken people there was no such thing as mental health awareness back then. Also they may try to solve problems based on what they would prefer in that situation. We know now that people have different coping mechanisms and what works for one person may actually hurt another. Though, his mom gave him 1 job....why did you let the Duke control you.
I get that the duke is hated by the everyone because he neglected the duchess and yeah, (when she was traumatized and all).
A lot of stories where the MC [goes back in time] and changes their attitude for the better, a lot of readers get mad at the ML for "suddenly" taking an interest(/love) in the MC... it was the duchess who brought herself into this marriage (heck, I'd probably too. To leave that 'father'). Imagine having a wife who couldn't even speak for herself, or even properly take care of her own baby (I get she's has trauma, and it shouldn't be dealt carelessly). You're probably happy and excited for the MC to finally take charge and that confidence, to see her shine bright, right? (Wonder, where that "interest" came from?)
I'm not saying that what the Duke did was justice or okay because of his background or his past. (But you can't really say the MC wasn't at fault either)
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Even today, we don't know everyone's past, their traumas/problems, and such, we can carelessly say or do things to others (even if ours/their intentions were for the good). Even small comments, you may think its not so bad, but those small comments can build-up.
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Honestly, I just keep writing. Didn't think it would be this long...