The public realm in America has two roles: it is the dwelling place of our civilization and our civic life, and it is the physical manifestation of the common good. When you degrade the public realm, you will automatically degrade the quality of your civic life and the character of all the enactments of your public life and communal life that take place there.
Edit: There was some talk here a while ago about roads that were built by developers "for free" and then given to cities for maintenance. Sounds good on paper but results in ridiculous amounts of roads being built... Anyone remember a good link for that?
Also, OT, but "The New Topograpphics" is a great and seminal photographic book about the new American Landscape.
Many people reach a point in life where they want to live somewhere with a slower pace of life and less disturbance than the city. That's why suburbs exist.
Classical optimist / pessimist outlook on neighbors. You're optimistic you'd like your neighbors and so would everyone else. I live in a neighborhood stuffed with teabillies and multiple time convicted DWI alcoholics and sports/tv addicts. I'm perfectly happy not hanging out with the majority of them. Somehow, I'm guessing they're perfectly happy not hanging out with me. Now don't confuse wanting to associate with wanting to respect each other. VERY libertarian where everyone has the opinion "they don't mess with me, I don't mess with them" "no problem for me, means no problem for you". I REALLY don't want to live somewhere non-free where everyone is all into everyone else's business.
Technology means you are not forever enslaved to interact solely with people who's only connection with you happens to be, being nearby you. I like that.
Where I grew up, in the country, about 50% of the people had something to do with the community that they lived in. The other half were people living in the ex-urbs, commuting to the state capital an hour away or some other place.
A 5 acre lot ex-urb is the same as a half-acre suburb, just a bigger lot and bigger lawn mower.
The "city", even low-density parts of a city with say 50x100 lots and detached housing is different. You interact with your neighbors (for better or for worse), share public utilities and your kids walk to a bus stop or walk to school vs. get picked up at the door.