You can live on an American diet and still feel good about yourself, even as a fatty. If eating tasty food makes you happy, yeah, they have a point.
Okay, but then they wouldn't even know that makeup existed, which means they would have had to found it out themselfs which would them put into the position of pioneers and result in a prove of their point.
Chicks had to rely on the tribe for ages so that makes them sensitive about its approval. It is a herd mentality, one chick does it and sucessfully attracts a mate, the followers copy it and the rest don't know the root cause of it. It makes them feel good, cuz they gain ego gratification of the approval of others.
People who don't dress for others are credible in that case, they are basically dress for the sensational feeling. I couldn't care less if someone approves of my skirt wearing but there are limits to it as long as you cannot survive on your own.
It is not irrational but subjective, I like the feeling and comfort, it ostensibly reduces the chance of scrotal cancer and improves sperm quality, 100% disapproval is unlikely for the sake of survival - except you live in an religious fundamentalist country, I don't do it for others, because the number of people who publicly approve of it openly is very tiny, it is the next best thing to naked down there.