I thought the point of the article was that DG comes to town, puts the surviving local grocery store out of business, and then the only means of getting fresh produce and meat is to drive to some store at a distance greater than whatever USDA deems for a "food desert." Which can be problematic for some people.
In that scenario, a home garden and a few chickens seems to me like a perfectly reasonable alternative to supplement your food supply, and the USDA, whose whole reason for existence should be agriculture, might try encouraging that, rather than declaring places a food desert. Labels are a non solution to a problem.
Unless things have drastically changed, every state land grant university in the nation has a local county extension office staffed with employees of the local university school of agriculture, whose primary purpose is to extend knowledge of the art and science of agriculture, and keep people in the field up on the newest techniques and knowledge. These offices can help folks with things like this. Most people probably don't know they exist, but their taxes are paying for them.