Our town does have a bus system but most of them drive around empty or nearly so most of the time. We also have a decent indoor mall and several outdoor "big box store" shopping centers which all seem to be surviving if not thriving.
I'm also thinking of smaller towns. People may drive there, park, then walk around and enjoy it -- and spend money. There are towns like this around New England, for example. They're destinations people want to visit or live in. If instead the town had a Wal-Mart, it wouldn't be the same economic benefit to the town. Who would visit for that?
Of course even better if there were rail service to the town. I'm not disagreeing with you, there. I'm just pointing out that this isn't only an urbanista issue. I think it matters as much, maybe even more so, for smaller cities and towns.