I vastly prefer the perception of this world to the one in Parallel Paradise. Obviously there are differences, in Paradise they will literally die after a certain age without men, and there are literally no men (until the main character appears), but I just find the reactions the females (and males for that matter) have in this world to be more realistic (or likely).
Also, I don't particularly care for the incest tag here. Sure, his family certainly have the interest and intent, but considering absolutely nothing has happened (in this version, unlike the R-18 one, I assume) and it seems unlikely anything will happen, I find it utterly unnecessary.
And arguing that it's necessary to warn people simply that the subject matter is covered is the same argument that was dismissed by MangaDex staff for the request to add a "slavery" tag. I see more need for a "slavery" tag (that remains hidden unless a person extends the tags to "see all") than for the incest tag when the family only ever privately thinks about it. No act, no threat of the act, no need for the tag.
Could people be shocked by the subject matter? Yes. Triggered by a trauma? Yes. But the same can be said about the slavery subject matter. Both are outlawed in most countries on Earth, and both still happen regardless of the legal status of the act. They are both triggers for people who are alive, but this manga handles it far more lightly (as in what happens with it) than nearly any that handles slavery.
Anyway, that's my two cents.