On a planet this well settled, the only reason anyone would pay for a traveling doctor ... would be an unwillingness to go to a hospital. Hospitals tend to have Alliance presence, and security feeds, and requirements like legal identification. From what he sees of the few other patients -- a rawboned woman with a badly infected knife wound across one shoulder; a pair of heavily tattooed young men, one with a wheezing rattle in his lungs and a low-grade fever -- Simon suspects they may have reason to want to avoid that level of attention.
Which is just as well; so does he.
The work's done by this time, and the patients have gone. Sunlight sifts golden through the missing part of the roof, and Simon is packing up the last of his equipment.