Primary care NPs are good at what they do, but what they do is very limited - most of them will admit it. Anything they haven't seen before comes along, first thing they want to do is call an ambulance and send them to the hospital or a specialist - or they will pull in an actual MD to ask them what they should do.
So if an NP has 10 years of experience working in a primary care facility - what problem does it solve to somehow 'promote' them to an MD based on that experience? Will they magically now be able to see more patients per hour? How does that solve any systemic health care system issues? It doesn't - it simply allows them to get paid like a real MD, when they aren't - so if anything, drives up costs.