The original series, though, was in line with the space program of the 60s. Private enterprise stopped somewhere in the stratosphere or mesosphere, and Roddenberry saw that as the model for the future. It was logical for him to conclude that in frontier societies, government and the military predominate over private interests and private enterprises.
Now of course, that's not entirely correct. Whether we're talking Roman Britain or British India or the Old West, traders and tradesmen followed where pioneers and soldiers went. Deep Space Nine may have been an attempt to take that part of history into account.