It has, but so has every insurance. That's the reason things are out of control, the greed in the medical profession.
Greed? Do you have any IDEA what a doctor (or nurse, for that matter) has to spend on their education?
Registered nurses - at minimum - have four years of education to sweat through (that doesn't count specialization, such as psychiatric nursing), then they have a licensing exam (at the state level). Remember, that's the floor.
Nurse-practitioners, let alone full MDs, or specialized nurses (I mentioned psychiatric nurses earlier) have longer runs - up to ten years for some specialties (even in-demand ones like psychiatry or gerontology). It's not cheap - a typical NURSE starts their careers nearly six figures in debt merely due to student loans - figure nearly $200,000 for nurse-practitioners or MDs (and I'm talking general practice for both - specialization has a taller debt load due to taller education requirements).
Yes - there ARE programs that offer near-full-ride or completely full-ride scholarships (in the United States - the Public Health Service Commissioned Corps is one, and the military's Uniformed Services University of the Health Sciences is another); however, both require you to pay it back in sweat equity (a commitment to serve a certain number of years in particular capacities). C. Everett Koop was respected as a Surgeon General because he was in the Commissioned Corps before - not exactly typical for a Surgeon General. (No - it's NOT a requirement that you serve in the PHSCC before being nominated as Surgeon General; other than Koop, only Jocelyn Elders had served in the PHSCC before becoming Surgeon General.)
NO professional - in ANY profession - wants to be trapped under a mountain of debt forever; therefore, why would doctors OR nurses be any different in that respect (than electrical engineers, or any other sort of engineers, for that matter)?