It’s not a contest. Does he get a prize for not being physically abusive or related to her? Your defense of his behavior is essentially “he could be worse”, which really says a lot about how few decent qualities his character has. Also, what does her random family history have anything to do with his actions? She doesn’t know that history and neither does he, and even if she did it wouldn’t actually make a difference. So she is more accountable to her unknown family’s past behavior than ML is to his own?
It takes a hell of a lot more to be a decent (not even a good or great) partner than “not being physically abusive”.
This is a horrible story with an insidiously manipulative ML. ML is a Duke, but pretends to be the peasant best friend of the fl for more than a decade. She learns that she is going to be sold to the Duke presumably to be used for sex, then killled. She goes to the ml for help, hoping that if they marry, and she is no longer a virgin, the Duke won’t be interested any more. She is 100% upfront about what is happening and why she is proposing.
Despite the fact the ml is the Duke, knows that she isn’t going to be abused like that, and that he has the resources to protect her, he doesn’t tell her anything to make her less desperate or fearful.
His men swoop in and “rescue” her from people trying to kidnap her, only to imprison her in the Duke’s castle. ML pretends to be a gardener to see her and still doesn’t let her know what’s happening. She still believes she’s going to be assaulted and killed at some point. He is going ahead with wedding plans for two weeks without even proposing or clearing the air. When she finds out the truth he even guilts her into going along with it by painting her as manipulating his feelings and trying to exploit him.
He deliberately manipulates her by pretending to be sweet and vulnerable so she will do what he wants. He doesn’t care about her opinion or autonomy, and is happy to take advantage of her fear and desperation to get what he wants. Basically, the type of character who would rather manipulate her into an emotional and literal corner than actually try to win her over, because he knows he will never take no for an answer, so if it ever came out of her mouth, he would become the undisputed villain.
The fl is not a real character, but an accessory to the ml. She’s got the usual fl Jekyll/Hyde switch (basically a normal personality for when the ml isn’t around or doing something shitty, and a permissive doormat personality for when the ml treats her like property). Since accommodating the ml’s toxic behavior is a higher priority than the consistency of her character, behavior, and personality she gets watered down into a dumb, naive, spineless, and shallow character. The only reason the ML isn’t the villain is because the fl magically forgives everything instantly, and does not think or act like a normal person (or even her main personality) whenever she finds out the ml has lied to, manipulated, gaslit, disrespected, or demeaned her.