Even with "other types of insurance", the doctors may not be getting paid as much as you might think they are. They often have to have contracts with the insurance companies that say they will take a much lessor amount than your bill shows, or that you would pay if you came in with checkbook or cash in hand. So even if they discount for cash, as the clinic where my doctor works (yes, he 's just another employee), does, you still might be paying the doctor more than the insurance company (plus your co-pay/share) would have.
Many insurance companies, mine for example, are very slow payers. I'd get a different one, but it's the only one my company offers for "off-site" employees.