The idea that farmers markets are commonplace in rural areas is mostly BS. They exist in cities for sure, but you pretty much need an urban population (and probably a fairly well-off population) to really support a farmers market.
Just because farms exist in an area doesn't generally mean the people in that area are getting their food from those farmers (at least directly). That's mostly a relic of an old vision of farms that grew every type of produce and had a variety of livestock instead of the corporate monoculture farms that dominate today.
Sure, the truly rural people aren't going to farmers markets, but the people in small towns and suburban areas do (this is in contrast to the "big city" in the original comment). Most rural people use a store for most stuff and then go to farm stores/stands/neighbors for other things.
There are still farms that produce a variety of produce. Many of them only produce them as a small percentage of their operation. For example, the dairy farm down the road plants sweet corn, tomatoes, peppers, watermelon, cantaloupe, and (not food, but) manure. I know of several other farms that do similar things.
Just because farms exist in an area doesn't generally mean the people in that area are getting their food from those farmers (at least directly). That's mostly a relic of an old vision of farms that grew every type of produce and had a variety of livestock instead of the corporate monoculture farms that dominate today.