We took a similar approach to our kids; the streets were for cars and not playgrounds.  Our subdivision went in around 1980 and had two major attractions to us - sidewalks on one side of the streets with nearby Trails and Parks and Playgrounds. A real plus in that many of the houses had little if any back yard. Later subdivisions were allowed that had zero sidewalks in order to maximize the lot count for the developer.  We were faced with a developer in the '90s that had P&Z approval to add 40 houses to an already gross cut through problem; they had no back yards at all.  At one time city lot sizes were 15,000 sq ft minimum, today that size is driven only by fire code.  Sound familiar?