Periodically I remember to check the customer supplied photos on the Garden Patch Grow Box website. It is an interesting source of information. If you are not familiar with it, the Grow Box is a sub-irrigated planter (SIP) very similar to the EarthBox but less well known.
In any case, what strikes me is that the majority of the photos are of SIPs in the suburbs with this exception. There are a couple of others on balconies but most of the photos have grass lawns or contain some other clue that the location is suburban or rural.
My belief is that this is directly connected to the gardening consciousness associated with having a traditional yard. The majority of people intuitively think of gardening in the dirt. No yard, no dirt, no gardening.
Due to our retrogressive horticultural education, the lay public does not know that fresh vegetables can be grown in a SIP box or bucket anywhere there is sunlight. It does not matter if the surface is grass, blacktop or concrete. Who knew?
The other thing to note about these photos is that all the people are white. That reflects much about our horticultural institutions and education. People of color living in our cities are not well served by these institutions.
I live in New York City and see it first hand. Even though the city is a melting pot of races and cultures, the institutions of horticulture are predominately white. If we are ever going to solve our problems associated with childhood obesity this needs to change.