Incentives. Plenty of people would go into rural medicine if it wasn't paying crap and dealing with nothing but elderly Medicare patients because of the lack of health insurance for people just marginally above the Medicaid line. Of course this means there's basically no support currently for the hospitals and more than half are being bought up by private equity anyways and shipping it all to the smallest bottom line.
The medical cartel loves to cloak their policies under the auspices of safety. In the end you'll find their policies magically result in massive profits for bureaucrats and chokepoints that constrain the supply of gatekeepers. This is not accidental.