A friend asked me recently what I thought about hydroponics for the large scale production of food. I told him, truthfully, that it is the antithesis of all I believe in about where food should come from. The idea of hydroponics originates from the idea that we need some futuristic technology to feed the ever growing world population.
My main concern is further centralization of the production of food. If the technological overhead is too high, whoever owns the technology to produce the food, will have control over it. That is, the quality, the price, the rate of production, etc.
Over generations, the production of food has become more and more centralized. This decreases the resilience of the food chain. Whereas previously it was common for people to rely on themselves, their neighbors, or their immediate community to supply the staples, now such self reliance is the exception. One driving force of this is the increased cost and regulatory overhead of meat processing. The places you can process your animal have diminshed alarmingly. The parallel with produce that I am trying to get at is that eventually, the regulatory overhead to produce hydroponic food can be made cost prohibitive for the average person or community member.
The other problem is environmental. Large scale farms monocrop. Over time, this leads to depletion of the health of soil, later leading to desertification. When there is no soil left to grow your own food on, you then rely on future large scale hydroponics company.
Furthermore, I have serious doubts about the nutritional quality of hydroponic produce. Although we know a lot, we do not fully understand the interplay between soil and the nutrition content of the produce. I would find it hard to believe that a plant that is only fed nitrogen, phosphorous, and magnesium, is the same as a plant allowed to grow at it's own natural pace in healthy soil.
It isn't flashy or glamorous, and it isn't high tech, but traditional backyard or community farming works. And no, most people cannot or won't produce food for themselves, but within a community, there is enough, and there has been for millenia.