You're right, from an economic standpoint, at least on the surface. But what of the social and ecological benefits of keeping alive small communities and small fields with diverse crops? The problems with large-scale monoculture farming are well known. A counter-argument is that food is too cheap. That obviously doesn't feel correct for someone struggling to pay the bills each month, but still... Workers are being squeezed on one end and small farmers are being squeezed on the other, and the gains go somewhere else entirely while small communities fall into despair and die out.