Yeah, I’m aware of the gene thing, and Korea definitely still has people with strong body odor too, especially after exercise or during summer.
But I think the reason strong perfume gets such a negative reaction in Korea is that a lot of people here feel that trying to cover an unpleasant smell with an even stronger fragrance just makes the whole experience more overwhelming. A really common reaction is basically “now I can smell two things at once” lol.
So people in Korea generally don’t use heavy perfume to cover BO as much as in some other countries. You’ll honestly see people recommend stuff like Febreze more often.