Okay, let's move away from the gender thing a bit, is it inevitable that lots of black people had to be slaves because they were black? Or that Irish people were treated inferior by the British in colonial times on the grounds that their heads were supposedly smaller? (I'm not making it up.) Difference shouldn't automatically mean inferiority, but it does, because you have to explain inequality with some "natural" things.
Women are inferior socially --> it's a social practice to make up for this inferiority with their looks --> so then all women are equally seen as concentrating on looks (of their own and other women), even though that's what men do as well, I mean they also concentrate on women's looks --> it makes women concentrate on their looks even more, cause there's hardly anything else they could attract attention with. Even on the fucking faceless internet.