She does change. She finally learns consent from Haesol and you can see that in the scene where they did choking right. Mutual respect was shown in that chapter and yet...
Minho didn't deserve to be raped. She couldve done anything else but she didn't. Rape is not a natural solution, it's something you consciously decide to do. This is more about Duna's moral compass than about Minho. Look, I know you really admire her and I appreciate that but what she did was a crime. I love her too and I was praying she changed but she didn't. How can you be appreciated for being good and mature one chapter and then the next, you just assault a person. Also I'm not a Minho stan, I just sympathise with him after all that happened to him. All the terrible things he did were terribly punished but Duna hurt many people and raped her subs but somehow, she gets excused
Rape is rape and it's always wrong and is duly called out in all manhuas regardless. See love levelling, bj alex, kiss me liar, people always comment on the rape scene being disgusting. It's bad that we have associated that behaviour with male leads but I would like to add that it is still never idealised.
The point of most of those problematic bl's and love stories (like twilight, 50 shades of gray) is that by the end, the male lead changes by the power of love, thereby insinuating that the rapey, violent behaviour was never ideal and had to change. Duna got so much love from readers because they were eager to see her learn better and improve through the love she eventually gets, instead she keeps on raping her subs and it's somehow justified because she's a woman.
That's when people started hating her. Not all victims of verbal abuse turn out like Duna, who herself realises that consent is important as a 28 year old woman but still overlooks it to play out this rape fantasy. In Minho's case, just because people are saying that he shouldn't have been raped doesn't mean that they want to ride his dick or kiss his ass. It just means that noone deserves rape, no matter how annoying, arrogant or verbally abusive the character is written as.