The public transit angle seems like a red herring to me. My wife and I lived in cities for several years after law school. (New York, Baltimore, Philly, DC.) We didn’t feel alone in school, but felt quite alone after we graduated and had a kid. By contrast, now we live in the ‘burbs near my parents, and we feel far less alone than we have for years. We’ve got neighbors with kids we see regularly. We see other parents at school, church, the park, birthday parties, etc. We see my parents multiple times per week. Sure, we have to drive everywhere, but that’s hardly a deal breaker. (I see people more now that I have to drive to see, than friends I had in DC who lived in the same apartment building.)