Frank,
I would like to respond to you by first Explaining my unique perspective. My training started out as a PA in thoracic surgery and critical care medicine coupled as an AA (anesthesiology assistant). Then after a rush of insanity, I went to medical school. Completed residency and a little extra training and then went to work. As a boarded anesthesiologist in private practice,I have hired and fired many CRNAs. Needless to say I have Experience with all kinds of healthcare providers at all levels.
With all that, I learned how to put all things in perspective when I was on my first few nights OR/trauma/ICU call as an attending in private practice. During those nights, I would look over my shoulder and no one was there. The decisions I made and actions I took were mine alone. It was then that I realized what It meant to be a physician.
Non-Physician practitioners will never know what that's like because they will always have someone behind them.
When someone pulls on your superman's cape, just ignore them because they have no idea what they are talking about. Their In -experienced opinions are not worth wasting your time on.
In addition, it's not the number of letters or the type of letters behind your name, it is the patient care you provide that matters. There are many CRNAs and PAs who I would rather put me or my family to sleep than some MDs.

Nate