Healthcare requires cooperation among all these fields.

Physicians hold a high status in society and among healthcare workers because of their dedication to their job. Acquiring an MD is no easy task, it required 4 grueling and expensive years of medical school (after the 4 years of college and highly competitive admissions process). Practicing physicians then go on to complete 3 or more (usually more) years of residency, which is a demanding job with high levels of responsibility, and minimal pay. Many physicians then go on to complete a fellowship (1 to 2 years) in which they further specialize. By the time an MD is actually done with all their training they are well into "middle age" have hundreds of thousands of dollars to pay back and still need to begin their practice as as attending. This account doesn't even consider the professional demands of being an attending, and personal sacrifices made in pursuit of this career.  

Physicians earn their high status through their years of dedication to the field, and for most it is deserved. When M.D.s use their degree for commercial marketing of unverified products this is of concern to the healthcare field and the lay community because it calls into question the respect we have for all physicians. 

This same respect is not given to nurses, physician's assistants, or public health professionals. I do not necessarily believe we need to give this group the same respect. But I do think that our society undervalues their contribution to healthcare, and much of this is due to the poor understanding of what they do, and how they have earned their credentials. I think it is important for the health community to highlight the importance of the inter-professional cooperation required of all these fields working together within healthcare. This would bring about more respect for all these fields as well as healthcare as a whole.