I have experienced a similar thing in Colorado (used to live in a far-out suburb of Denver) and now Minnesota where I currently live. You wonder where all the people have gone! In the middle of a sunny weekend day, you know people are home, but it's a ghost town.

We seem to be lacking community resources and gathering places that create reasons for people to be outside. One very helpful community design element in the neighborhood we just moved into (Chanhassen, MN) is that none of the houses in our neighborhood have fences. We are located near lakes and wetlands, and they have a rule for no fences to allow wildlife to move around. It also facilitates humans being able to see each other, and gather.

Just yesterday, we saw our neighbors (who also have kids) outside and had an impromptu gathering as a result. This has happened often with various neighbors. Our last neighborhood was completely divided by fences around each house plot, and it was much harder to make connections impromptu. It felt very desolate even though we KNEW people were home a lot.

Not unlike what happens in open-office concept workplaces with well-designed gathering spaces.