That second link is what most of Chicago looks like. See for yourself: this site will generate totally random addresses in Chicago, and you can just copy them to Google Maps to see the street view.
The point, I think, is that the elimination of zoning is meant to upset the R-1 style of development you say is prevalent in Chicago and that I agree is conducive to kids playing outside, on and off the street. Where you have high density mixed-use urban development, outside play of that nature is much, much less common, as evidenced by my examples in Portland.
No, the alternative to R-1 development isn't "high density mixed use", it's 2-, 3-, and 4- flats. Pull up any random address from that site that's in Lakeview --- entirely RT-4 and above --- and you'll see kids playing on the street the same way.
This is the problem with the zoning debate: people exclude the middle, and say that zoning is either good single-family regions where kids can play on the streets, or terrible industrial zones that look like Giede Prime. We don't have to carefully reason through the alternatives --- good, functioning cities are full of them.
