Gardening is still a hobby. It's a matter of scale. The home gardener will get a few side dishes, salads, and maybe some tomato sauce out of the garden in their back yard. It is simply impossible to grow a substantial amount of food in the limited amount of space they will be using. Where I live, which is in a city by the way, if your crops are not protected by an 8 foot tall chain link fence, they will be pillaged by wildlife, particularly white tailed deer. If there was a real food shortage, your neighbors will be helping themselves too. There are also mites and blights that you have to deal with. Anyone who thinks they can really supplement their diet from a raised bed in their backyard has never gardened before.

I've been vegetable gardening for over forty years, and when I read about these urban garden fantasies I just have to chuckle. Growing food is a lot harder than it sounds. Most people can't keep a houseplant alive.