Too much reliance on cars for transportation and commerce built around that. Compared to Japan; we don’t have the opportunity for vending machines except when we are contained to a location without the ability to go to a store that isn’t that “far”. We have a larger scale of living; a half hour drive is normal to us, but a half hour drive for other countries is at the tipping point of finding a place to stay for the night and a vending machine selling a common foodstuff makes sense.

If you were forced to walk everywhere and “corner stores” were infrequent, vending machines would be far more common and worthwhile for owners of those machines.