Used to think like that too, but I try to think this way. Objecttively as a reader lmao.
I think its really done to show how much the people around Jeongyun does ACTUALLY treats him like a baby. The family themselves isn't exactly a bad person because they eventually does accepted Chaehoon and even liked him so much now after knowing what kind of person he is. The kind of person that didn't deceive their baby and actually loves him with all his heart.
It does seem cruel but I guess some act of blaming others is more likely to happen irl too because they "didn't understand" at first yknow? Its probably how the author shows how the family of a gay men actually feels? I mean not all family will be so accepting at first, nor not all of them will kick the son's ass out immediately. This is probably to potray how a family that gets along well but didn't understand gay couple react.
I mean, Jeongyun would definitely get mad if he knows that Chae-hoon had been receiving hate from his family at the beginning. But it was a way Chaehoon and his family chose because they knows how kind and emphatetic he is that they're trying to "get a grasp" of what kind of world and what kind of person his partner is before Jeongyun finally decided to actually open up to them. Now, even if he opened up to them, it will just all be smiles and laugh! Cuz they've been preparing. There's even no need for the author to show the coming out scene because now they will obviously happy with it.
How is that? Does this able to change your way of seeing the story?
Oh hell nah. This is really disrespectful towards the uke, they're treating him like a baby who can't handle the fact that his family does not like him being gay. If I personally find out my family did what Jeongyun's family did, I'd be fucking livid. He's not some damn kid that's easily influenced the way they're claiming him to be, even blaming Chae-heon for their "baby" turning gay? Well, guess what? YOU'RE BABY'S BEEN GAY FROM THE START. And he probably didn't come out to y'all because he felt you'll react the way you did. And I'll forever be annoyed they didn't resolve the issue with Jeongyun's family because it's so important to him, he was getting anxious over it.
In real life, hiding anything from your partner regarding THEIR family would never work out. This is bullshit.