One of the frustrations of dealing with proposals like Mr. Bittman's to create more small farmers is a knowledge of history. We've been there, done that. Our history shows small farms being consolidated into large farms, small farms going out of production and reverting to trees (see New England and New York), small farms being converted to suburbs. Our history also shows repeated "back-to-the farm" movements, sometimes with government support, as here.
My point is, not that small farms are bad, but they have vanished for economic reasons. Unless and until the food movement comes up with structures which change the reasons, small farms are doomed.
Now niche markets will work for some, but they don't represent an "answer" for America, just for a subset of Americans who can afford the tab.