I think you're right overall, but a lot of that is an unexamined reaction to a built environment designed for motor vehicles, rather than being designed for humans. In suburban America, it too often doesn't occur to people to walk even modest distances, and when they decide to try, the experience can be scary considering that they're likely to interact with inattentive truck/SUV drivers while crossing intersections. If I just crossed the major intersection on the way to work without being paranoid about vehicle traffic, I'd probably be wheelchair-bound by now.