Sustainable urban areas?

There was an interesting Letter to the Editor yesterday in the Seattle Times.
"Subsidies for the boonies
Why is it always people living out in the hinterlands in places like North Bend or Snohomish or Gig Harbor who whine the loudest about high taxes in their letters to the editor?
If their taxes are indeed high these people should take a look at themselves. They're part of the problem. In no small measure people living in the low-density boonies are a greater burden on state and local governments to provide schools, roads and highways, sewer, water, police and fire protection, etc.
It costs way more than they are paying to sustain that far-flung low density. The reality is that we who live in efficient, sustainable, denser urban communities subsidize outer-suburban and ex-urban development with our tax contributions.
If people living on the fringes want that lifestyle, they should quit crying. They're getting off easy in not having to pay for the true cost of that choice themselves. It is city-dwellers who should be complaining!
— Mike Moedritzer, Seattle"


Mike Moedritzer is complaining about all the people in the “hinterlands” complaining about their taxes being too high. He uses “sustainable” and “urban” together in the same sentence.

Urban centers are sustainable, huh? Funny, considering the city of Seattle essentially produces zero agricultural products. How can any urban center be “sustainable” when it produces none of the food it consumes?

Mike seems to think that Seattle could exist completely cut off from the outside world. I guess he doesn’t realize that starvation would set in rather quickly. When he hasn’t eaten for a few days, maybe he’ll realize that if he wants that lifestyle then he “should quit crying.”