
The rose-coloring is a common trait in fictional stories. This is not an exclusive phenomenon to the BL community, not even to the anime and manga community. In general, the trait of rape and violence is not fully understood by the readers and creators, so that (faint) Stockholm Syndrom is mistaken for love.
I do think a 180 ° turn is possible, as his behaviour is a common one for aristocrats who treat the ones under them with force but can act differently to their target of desire. But of course, it has to be pointed out that there is no clue how Seungho treats persons he loves (like family members or true friends). I am waiting for backstory. His behaviour towards NaKyum is - of course - UNEXCUSABLE. There is a lot to be made for, even if they do not end up as a couple.
However, I want to point out that the fangirl-affecting for Seungho probably derives from the fact that a reader wishes that there is a couple and from the current story Seungho seems to be the more preferable one according to the opinion of most readers.

Yeah they are both pretty damn terrible. But like if I had to choose one lol actually nah i choose FREEDOM!!! Screw them both! jk jk I guess the reason id say i was more salty with Inhun is because ive dealt with people who were a lot like him. A wolf in sheeps clothing type of deal. But like Seungho a violent murderer and rapist, master manipulator....so yeah. Both just as bad xD so true though i am ready for anything Byeon throws our way! Like its just such a well written story even though there isnt heavy amounts of dialogue. Truly genius.

I think people are so used to this yaoi trope that even when the story is not supposed to be romantic, the act itself is seen as a sign of love. There are even people who said that he didn't say no so this doesn't count as rape. This is one hell of a delusion. The whole manga is about this abusive relationship. I feel like this should be seen not as a "Bj Alex" but as a "Nii-chan" type of story where, even it they do end up together at the end, it's not because of some love delusion.

But does it HAVE to be a generic lovey dovey couple? This story was never romantic from the beginning, why does there have to be a neat love dovey couple at the end like every boring romance novel? Does that even fit the theme?
My problem is not ppl who want them together, there are plenty of ppl shipping them by his actual personality, who enjoy his good and bad sides. My confusion is with ppl calling him gentle while he threatens Nakyum and saying he doesn't know how to handle his feelings when he is pretty obviously aware that he desires Nakyum. He shows that in the next chapter pretty well but I won't spoil.
My confusion is ppl trying to water down the severity of his actions. I think he will turn out to be more sympathetic in the end but sympathy is not the same as straight up watering down someone's actions.
It's so weird to me when people try to paint his obviously cruel actions as him not understanding Nakyum and him having to come around. I don't get how yall can hate Inshit with your whole chest but use kid gloves with Seungho like he's not just as bad.
At this point he pretty much said he knows everything that's going on including the fact that Nakyum is terrified of him and ran away because he doesn't want it. He understands very well what he's doing, maybe he's never experienced infatuation before but he knows very well that he wants Nakyum as more than another piece of ass.
He just doesn't care how he gets to Nakyum's heart. Yall saying "Once he realizes his feelings"? He don't realize them now? He seems pretty aware to me.
In my opinion I think people don't really like Seungho for who he is. People keep calling him hot and saying how he can develop and trying to dumb down his cruelty like that's not one of his most interesting things about his character. Nothing wrong with seeing him as hot, he's supposed to be seen that way, but he's so much more than your typical "hot seme" who goes from rapist to lover. That lazily written BJ Alex, Viewfinder type top does not fit this story.
Not saying he can't develop but he's not developing into a lovey dovey boy. He's a selfish prick and no matter how you try to twist it he reveals every chapter that he knows exactly what Nakyum is thinking, he absolutely knows how much he hurts Nakyum. He just doesn't give a fuck.
Look at the way he reacted when Nakyum started crying. How he could've stopped there but CHOSE to make himself the victim by making it seem like Na was trying to provoke him. People don't even seem to read the dialogue sometimes. People take the little bit of vulnerability he shows and runs with it, trying to argue he's smart but then turning around and treating him like some clueless child when he does fucked up stuff. He's not just emotionally ignorant, he also lacks empathy, period.
I never understood people who stan villains but don't want them to be a villain. Watering down Seungho's actions and continuing to hope that he does a 180 and acts all lovey dovey and out of character seems like something a fan wouldn't do. He may not be romantic interest material (he could be in a fucked up sense I suppose) but he's super interesting as he is. Even if he develops I don't think his fucked up side will go away but isn't that what keeps the drama ripe?
It's like some Seungho fangirls don't really like him for who he is. I could be wrong but the rose-colored shades are there, everyone else seems to enjoy him as the dom he is and fully accept that he may always be a selfish prick.