A nice article on The decline of the American lawn by Tom Vanderbilt in Slate Magazine.
Growing up in Columbia, we had neighborhood tot lots, with communal swings and slides and on-property playgrounds were discouraged if not banned by architectural covenants. Those tot lots were pikers by the community playground standards I see today in some parts of the Twin Cities, though down our street is again essentially a tot lot built on a parcel adjacent to the freeway (probably from land surplussed after freeway construction). Few houses in our neighborhood have the play equipment Vanderbilt decries. When lots are small, people need common space. When lots are large, this can be internalized to their own property. This is of course the fundamentally the same as the third space argument of Ray Oldenham's The Great Good Place, where cities with smaller housing units have more common "third spaces", while when people have larger houses, they have less need (and perhaps less opportunity) to get out.