The thing is large stations in planitary orbit are much more structuraly rigid and stable. Compare Newark to the ring, and the ring looks very feeble structuraly.
The appearance of the modules is fine for houses but some of the big trading companies would probaly have their own unique designs build, especialy for their headquarters. The same applies to the Outcasts, Corsairs, Order and Nomads. All these factions would have build their bases from scratch by their selves.
