I'm not sure there is an explicit moral to Gordimer's "Six Feet of the Country." More likely is the fact that her intention is to make readers come to an emotional realization similar to that of her characters.
From one perspective, we see the young man who dies struggling to make a life for himself, risking everything for a better life, all to no avail. In the end, neither he or his family are even capable of purchasing a small parcel of land for a grave.
From another perspective, we see the white employer struggling to make sense of the confusion and tension created by the policies of a bureaucratic government that make such simple tasks so exceedingly difficult simply because of the color of one's skin.