> Consider, for a moment, that a woman may not want to be a mother
Then she is not likely to get the same respect as a woman who does want to be a mother. Respect for women who want to be mothers, and not respecting women who do not want to be mothers, is something that naturally evolves in a culture that values its population. This is because women who have genes and/or memes that cause them to have more children will spread those genes and/or memes more widely than women who have fewer children because they had a genes and/or memes that caused them to not want to be a mother or not have so many children. This would be reflected in the culture in that women who want to be mothers would be respected more than women who did not want to be mothers. The same thing can be said for men being fathers.
> or more realistically, that's not all she wants to be
I never said anything about women being _only_ mothers. The best mothers to raise the next generation are those who, first of all of course have children, but then after that, have an education, are able to dream and aspire of other things, and pursue those opportunities.
> Many Asian cultures are notoriously sexist.
You say this as if being sexist is a bad thing. Men and women are different, and this is reflected in the fact that every culture has different social roles for men and women. There is nothing wrong with being sexist, it simply arises from the fact that men and women are biologically different. The problem happens when women are judged by what men are supposed to do, or when men are judged by what women are supposed to do.
> Saying a culture cannot survive with misery is something you invented.
No, it simply stands to reason. You cannot subjugate the females in society, generation after generation, and expect it to survive. The psychological effects would be passed down to the next generation, and the fabric of society which raises the next generation, would unravel. Just look at the effects on children who grow up in abusive households. Now extrapolate this to an entire society. The results would be catastrophic.
> Often the coping techniques include (surprise!) investing all her energy into making her children accomplish by proxy (speaking of asian cultures, sound familiar?) what she could not.
All parents, mothers and fathers, want their children to accomplish what they could not. This is not limited to mothers. Fathers will also use it as a "coping technique". Say a father wanted to go to the city and get an education so he could have a bigger house and more luxuries for his family, but was unable to do so in his life. Would he not encourage his children to pursue that? Of course. This has nothing to do with the issue at hand, namely the subjugation of women.