Does anyone still live with that kind of family-model? '2 people + kids / 2 incomes' is pretty much standard where I live, no one can afford otherwise -- not even the higher-earning income bracket.
Some of that is about how the tax system works in the US, too - the way that "married filing jointly" works was designed under the assumption that married women are homemakers, and so treating two-income families fairly wasn't a priority.
If one partner made enough to support the whole family and you had kids, then I imagine there are some families who would want a full-time parent caring for their kids vs relying on daycare/parents/nanny.
Ahh, I see... That's actually a rational argument in favour of it. I sometimes tend to take conditions on this side of the Atlantic for granted -- like 90 € / month [+reduction for lower-income parents] for daycare / Kindergarten.
When a 3-bedroom house can be had for $150,000 or less, you can get by on a single unimpressive income. It looks like that income could be just $40,000.
If you are higher earning, then you can go well beyond that. You can get acres of land, a dozen kids (my choice), a McMansion, and so on. This is how it is for my coworkers and I, living along the Florida coast.