Public Space, Public Dollars and Better Practices

I was recently enlightened that Harrisonburg's Farmers Market, while a tremendous asset to the city, and even neighboring counties, for what it provides in business outlets and local products of all sorts, not only has a waiting list of vendors wanting to participate in the market atmosphere, but is also not accomodating those businesses by letting them participate in the open space that is clearly available on the outskirts of the pavilion space.

There seems to be lots of open area not being utilized that could be for these participants. What is the factor(s) that allow some to participate, but not everyone in this publicly funded, publicly available space?