The answer is multifaceted, but part of the problem is that some of the major reasons are extremely politically inconvenient. For example, what are the economic consequences of women entering the workforce in large numbers in recent generations? Increased labor supply drives down wages per employee, then more two income families increase price inflation (especially real estate prices). Together they transfer most of the economic value of women working into the hands of employers and existing land owners, when the economic value of the domestic labor it displaced had previously gone primarily to the woman and her family. And people who remain single are extra screwed because they suffer the same wage and price consequences without the second income.

But for cultural and biological reasons when one spouse is a homemaker it will almost always be the wife rather than the husband, so policies that would increase the standard of living by reducing the number of two income families have consequences anathema to the left (fewer women working) and the right (less value captured by employers and land owners). So we don't talk about it.