A great essay over at Crosscut.com explains why two different schools of utopian city planning in Seattle both try to ignore the city's present-day realities and historical features:

All sides in civic debates draw on uptopianism. There is a sense that we can have it all here: prosperity, nature, industry, wealth, social justice, growth, solitude, wilderness, a clean Puget Sound. The problem I have with the utopian impulse (which I too possess) is that it is often driven by two false assumptions. First, that there is only one way to do things right. And second, that the city or region is a tabula rasa, or a new iPad.

Utopianism is reflected in both forces for change, especially in the desire to break with the past. Those who would recreate New York (or Vancouver or Copenhagen) here are usually for starting from scratch. They tend to dismiss local history and customs and the older built environment in favor of whatever moves most boldly in the direction of rebuilding. ...

Those idealists who want to escape from New York (or Los Angeles or the Old World) to create something new also work on the blank-slate theory. They tend to see local history as easily swept aside. The severing of connections is crucial, or the remaking of consciousness. Any New Age must, by definition, be new. You see this in expressions of the urge to drop out, or secede, as modeled in Ernest Callenbach's 1975 novel Ecotopia. Our Cascadian region and its cities are often imagined as something apart, remote, or separable from a more corrupt or compromised whole: Seattle, Portland, Vancouver are metrotopias to be perfected and copied, even envied.

For both tracks, this actual place doesn't matter much except in that it is ripe or uniquely situated or timed for radical transformation.