I think that what you were seeing on Ardana was basically a economic class system. The upper crust, the rich and the ruling leadership live in the cloud city. The miners were a part of the society's lower class, or possible the lower middle class.
There were others in their society, artists, artisans, police, servants, farmers. Someone built that city, I doubt it was the wealthy. Someone invented the anti-gravity that placed it in the sky.