If adopted on a large scale, locavorism can only re-create the misery inherent to subsistence agriculture.
Everywhere the new Americans pursued a subsistence agriculture which supported some other major economic activity.
In the absence of barter economy, the economy might have ground to a complete halt and deteriorated to subsistence agriculture.
Farming that provides enough food for the farmer and his family but not enough for sale. By comparison, commercial farming is farming that provides products for sale.