Professional salaries to health care providers account for only 8% of total health care expenditure.

So what? When you pay for services - either here or in other countries - "professional" salaries aren't going to be the only component of cost for providing those services. If you're getting a medical procedure done, the reimbursement rate will cover the cost of the building and equipment, the medical supplies used in the procedure, utilities and power and heating and cooling, the costs of all the "non-professional" salaries like nurses and technicians and orderlies and janitorial staff everyone else (in the op-ed you cited, they're only talking about doctors), and everything else. It's hardly surprising that only a twelfth of that is going to the handful of people who hold an actual medical degree, and not the countless other people and equipment and materials. And it's not just health care services that are provided by doctors - it's physical therapy and home health care treatments and nursing home staff and the countless other things that are health care expenses covered by insurance (private or Medicare) that make up our annual health care expenditures.

We pay more for all of that. Twice what other countries pay. You can't reduce our overall health care spending in any material way unless you're willing to reduce what we pay for these services. The form of insurance structure doesn't matter - we pay twice what other countries pay both within Medicare and without.