I don’t think parent was denying that, or at least I don’t get a sense of this dichotomy in the text. As someone that lives on Vashon island (what some consider a suburb of Seattle; but I actually consider rural King County), I got the sense that suburbia here was specifically directed at the endless tract of housing one (so like East Bellevue, Kent, or large parts of Kirkland), but not actual small towns around the main city (like Bothel, Lynnwood, Kirkland proper, or—well—Vashon) or even other dense urban areas like Burien or Redmond.