Do you want to eat unregulated Chinese mystery meat? Not that I agree with the sentiment of 'holding the urban areas hostage' but the US and the world need the agricultural production of the central US
California actually provides most of the produce (vegetables fruits and nuts) for the nation. The midwestern corn / soy / beef states are focused on producing bulk commodities for export to other countries.
Yes, you are correct. My comment implied that a healthy population needs both. The agriculture crops are equally necessary for calories and protein