The two pictures below illustrate the vast difference between urban and suburban commercial shops. The small, locally owned grocery below is human scaled and inviting. The suburban corporate shop is isolated and unwelcoming. Even though it is likely that many users of the suburban store arrive via foot or bike, the design is geared totally to those who arrive in a car: the building is set back a far distance from the street and the front door faces the parking lot, not the sidewalk.
Both stores probably serve similar sized populations, but the suburban area spreads out over a much larger area, making walking unpleasant. No walking equals no need for storefront displays and open doors. This becomes self reinforcing: since no one walks anyway, there is little that is done to make walking more pleasant. Cars then become the default transport mode, which contributes more to the unpleasantness of walking.