The U.S. is huge and spread out. Not everyone has the luxury of having all their needs within a 10 minute bike ride. We need that automobile infrastructure to get places so it makes sense that it is prioritized.
But you've got it backwards. The point is that the "spread out" nature you're talking about was created with the idea in mind that everyone will have a car and will drive. That was a conscious decision, and not a necessary one.
Also realize that it was by design that you don't view having a car to be the luxury.
On a large scale, yes. But urban sprawl is directly caused by the automobile.
The design of US cities is just godawful from any perspective (environmental, social, business efficiency, crime rates, ghettoization, etc), compared to those in Europe. I'm fairly certain that Manhattan and San Francisco are so vibrant and livable largely because they're constrained by geographical barriers.
The urban cores are very old, but many of them are surprisingly small, with the bulk of the city dating to the past 100-150 years. Copenhagen's old center, for example, was less than 10km across (confined within city walls until the 1850s), so nearly the entire city was laid out according to 19th- and 20th-century urban plans (the 20th-century one was http://en.wikipedia.org/wiki/Finger_Plan).
The city where it's architecturally most visible is probably Barcelona, where you can see the medieval core's winding streets, and then a massive expanse of centrally planned regular squares outside of that: http://en.wikipedia.org/wiki/File:Eixample_aire.jpg
I thought it was people fleeing the inner city for the suburbs that caused sprawl.
It sucks, but so do the cramped cities like SF and Manhattan. You can never get a moment's peace and contemplation, and they're even more crassly commercial than your average strip mall.
Sure, it was always large, but suburban sprawl was not always a thing. As cars became ubiquitous, things got more spread out, and designed with cars as the assumed primary mode of transportation. This was not necessarily a good idea.
Or it could be that not everyone wants to live in a crowded city in a small apartment. Some people prefer to be a bit more spread out, perhaps near nature.
The US was huge and spread out before the automobile was invented. People used to live close enough to local markets that they could get by on foot, bicycle, or horseback. We used to have train stations everywhere, enabling long-distance travel, but day-to-day travel did not require mechanization.
There is no reason we cannot create towns and cities where people do not require cars. New York City is like this (having grown up there, I did not get my driver's license until I was 25 and living in a different state). We can create local transit systems with buses, trolleys, and light rail. The only place where cars really make sense is in very rural areas, where the population is extremely sparse.
