And the idea that we are going to go back to small, multi-crop farms seems ridiculous when the trend has been the other way for centuries.
[WS:] You are right on this, comrade, it is a bunch of nonsense from a rational point of view. However, this is not about rationality but about feeling good about oneself. Many people are genuinely concerned that the American life style is unsustainable and devastating for the environment, and even want to do something about.
The 100-mile diet is a craftily designed symbolic gesture that allows people to think that they are doing something without actually doing anything. It has all the hallmarks of a "protest" movement - anti-corporate tone, "small is beautiful" feel, the emphasis of everyday ritual (like going to farmers' markets, health food stores, all the small talk surrounding it, etc.) - that appeal to an individual by creating an illusion that he/she is doing something to solve a social problem. However, it does nothing drastic or controversial, it does not address the root causes of that problem (e.g. changing land use patterns, transportation, energy use, etc.) In that respect, it is like alms giving in the middle ages - it made the giver feel good about himself thinking he would go to heaven, made the church rich by acting as alms giving intermediary, but otherwise it did not make a dint of a difference.
Wojtek