Really girl? You should goes see outside your world and stop being prejudice. Some of western people really have no weight to calling our common sense and tradition as disgusting. It really an offense. Never did that irl please. We eastern may raised to be polite, but there are things you shouldnt said.
i mean they are kind of speaking the truth, and risking the baby to have mutations that can lead to health issues and also being an outcast or something weired/monster because of it, and it may also be a problem for the parents if the child have health issues and cant go to the hospital because of money. you know there is a reason why incest is abolished in the rest of the world right? And incest is not tradition, it might be leaning more about the culture, but not tradition. The only excuse for the royals doing it is because they wanted to keep the blood "pure", there is no excuse for normal people to inherit that culture. Moreover even now most royals have abolished that mindset already, if having incest be part of your tradition and culture, then there is still no progress in your country, and from that i just know that women in your country dont have a lot of rights.
i literally dont know why mangakas like to ruin their stories by adding incest like wtf