Enough to buy a building, pay staff (half a dozen nurses and clerical staff), buy office supplies, pay all of the ridiculous fees and licences they have to pay each year, building and lawn maintenance, malpractice insurance, lawyers (because people LOVE to take a doc to court.....cuz their "rich"), accountants, cleaning contractor, and keep some for themselves. What? You think the docs just keep every dime that comes in the door? They are running a business just like the doughnut shop and the mechanic.
So, yes, they have to try to keep a full schedule to pay everyone else and themselves. Sometimes that means someone will have to wait extra time. So be it. If you don't like it, go to the doc in a box. They will talk to you for 4 minutes and write you a prescription and move on to the next 47 patients......if you call that medical treatment.