I don't think you can really extrapolate from generational history here. As recently as the 1940s, most kids were raised in the city or in rural areas. You've got maybe three generations raised in the suburbs. Not exactly ancient history.
It's also worth noting that what the suburbs are is changing to become less car dependent. Lots of people having kids in new developments in Reston, VA, which is a suburb but organized more like the bedroom communities of yore (with a little downtown) than the sprawling subdivisions that prevailed from the 1960s to 1990s.