Not everyone can have a garden in their backyard--if they have a backyard. If people driving to buy food makes you shudder, I wonder what a nation of shut-ins eating their government-allotted-and-delivered-by-vehicle bread would do.
I've tried biking to supermarkets in America but the closest has always been like 30 minutes away, and I need to have a crate just to sanely carry a decent amount to feed my family.
May not be representative, but it was sure nice always having fresh food nearby.