Earlier quoted context omitted.
Because, then the single payer, can say "your policies/prices don't work with our system", fix it, or we won't cover any patients, effectively shutting you down.
What is stopping insurance companies from doing that now? If you're paying for insurance, it's in your insurance company's best interest to pay low prices.
I actually agree w/ overhead limits, but you also need other efficiency metrics to keep the anti-optimization in check. Or, personally I think we should go to some form of universal healthcare and wipe out private health insurance as it's currently constituted.