In my mind there is no excuse. If you're so ignorant that you don't understand the economic implications of modern medicine then you're not smart enough to be a doctor.
"I got me a degree, here's a prescription for an ototoxic drug."
If you are trying to help people by being a doctor then it should be your entire focus on life because there's still so many unanswered questions about the human body. They probably only know less than 20% of how the body works at the very tip top of the research community. Your average GP or PCP probably knows less than 1%.
Basically, most people are stupid, regardless if they are wearing a white doctor's jacket, a police badge, a judge's robes, or priestly frock and not only are most people stupid, many of the smart ones are greedy liars.
This is why our Lord has educated us saying, "I am sending you out as sheep amongst wolves, therefore be wise as a serpent and meek as a dove."