My kindergartner is now at the point where he can walk into a random town event and find somebody he already knows. He's had 3 consecutive weekends of birthday parties, with largely the same cast of characters at the last 2 (the third was a pre-school friend who lives in a different city). He knows all his friends' parents, and a bunch of them apparently know me ("Hi, ___'s dad!") even though I can't remember their names. There's an interlocking web of social relationships in the city that we've somehow become part of, where people know other people through other contexts.
This didn't happen automatically, and it's been fascinating to watch the work that my wife and other (frankly) women have done in building the village. It's a slow, year-by-year process of doing favors for other people, putting yourself out there, spending time with other people, having your kids spend time with other people, opening up, and building trust. We tried carpooling for the first time last spring - it worked out great, and we have a much closer relationship with the other family now, but it can be nerve-wracking entrusting your small child to another driver. But that is how you build trust, and trust is how you build the village.
The community I live in is not at all what the article would predict. We are a secular liberal family. Our friends are mostly secular liberal with some religious liberal families mixed in. The community is 30% foreign-born, and 35% speak a language other than English at home. It is racially mixed, But the most important ingredient to having community is that you have to want community, and value it, and be willing to put in the effort to build it. And it has a critical mass of people who value community, enough that if you are one of them, you can find your people.