Maybe many weirded out by the fact they grew up as siblings. However the didn't read the details. First the situation in Lagrange is not familial environmant at all. The children killing each other to survive. Second the FL knew from the start that they aren't related because she is a transmigrated person with her memory of the novel. She act like a cute sister to survive. Third the ML also knew from the start that she wasn't his biological sister and never thought of her as sibling and just let her get close because he didn't bother at first then he was amused and curious and he learn about affection from her and still he didn't think of her as siblings. Fourth even though they grew up together they didn't even met that often and ML always out on mission and later they were separated for years when ML went to war and met again when they were teens. And last the story is in the kingdom era not modern world. In that era sometimes nobles even adopted other nobles daughter to be their son's spouse when they grew up. Even in other kingdom in another nation, step siblings get married to maintain a pure lineage. Of course this happen only on some region. So when we use our modern standart to judge a middle era story it was a little bit out of place. Some even get married at the age of twelve in that era and consummate their marriage in their fifteen or sixteen years old. People who read a lot of history from many countries wouldn't comment like that because they know what era the stories are. But if it in the modern era than it really a bit nauseating. I don't like incest story also but it also depend on the era of the stories and the context of the story.
Maybe many weirded out by the fact they grew up as siblings. However the didn't read the details. First the situation in Lagrange is not familial environmant at all. The children killing each other to survive. Second the FL knew from the start that they aren't related because she is a transmigrated person with her memory of the novel. She act like a cute sister to survive. Third the ML also knew from the start that she wasn't his biological sister and never thought of her as sibling and just let her get close because he didn't bother at first then he was amused and curious and he learn about affection from her and still he didn't think of her as siblings. Fourth even though they grew up together they didn't even met that often and ML always out on mission and later they were separated for years when ML went to war and met again when they were teens. And last the story is in the kingdom era not modern world. In that era sometimes nobles even adopted other nobles daughter to be their son's spouse when they grew up. Even in other kingdom in another nation, step siblings get married to maintain a pure lineage. Of course this happen only on some region. So when we use our modern standart to judge a middle era story it was a little bit out of place. Some even get married at the age of twelve in that era and consummate their marriage in their fifteen or sixteen years old. People who read a lot of history from many countries wouldn't comment like that because they know what era the stories are. But if it in the modern era than it really a bit nauseating. I don't like incest story also but it also depend on the era of the stories and the context of the story.