I take two sides. Ideal versus Real
IDEALLY, the Father must work and provide for the family. The Father has a social responsibility to the family. The Mother must stay home and take care of the kids. The Mother has a psychological responsibility to the family. A mother cannot be easily replaced because of this psychological relationship from conception until birth. Ever wonder why a child forever clings to the mother even though the mother scolds her child? The Father can easily be replaced by an Uncle, Older brother, or anyone that can represent a father figure.
However, because of the REALITIES in life, a lot have changed. Women's lib is not even the issue anymore, our whole lives, cultures, behaviors, etc. have changed. Even doughnuts have changed!
Women work not because of womens' rights anymore. It's because they need to.
As to watering down the family unit, I don't know about Americans, but I myself find QUALITY time for my kids no matter how busy my schedule is. My wife works and she does the same. It's a matter of attitude and setting your priorities. We have 24 hours a day, 8 hours sleep, 8 hours work, 2 hours travel time a day, and several hours for other stuff. What's left for the family and kids? How do I manage time? I don't work overtime, I don't answer office calls after 6 pm, I don't (never) bring work at home, limit watching TV at home (instead we talk and play), limit internet at home (I do this in the Office Lol!), etc. etc. etc.
There's a saying: As the water shapes itself to the vessel that contains it, so a wise man adapts himself to circumstances....