"Professional courtesy" is a curious phenomenon.
Early in my career, it was held up as a standard, and even the clergy came to expect no-charge visits or at least discounts. When it was occasional and voluntary it was fine.
As time went on, it became more of a burden, and sometimes it was a problem do determine who was doctor (dentist? chiropractor? podiatrist? naturopath?) or clergyman (I had a few pull out their Doctor of Divinity by mail cards), and whether his/her entire extended family was also entitled to discounts. When it reached the stage of "entitlement" I became resentful.
Medicare to the rescue! -- Medicare decided that the practice was fraudulent. That was good enough for me. After all, physicians can for the most part pay their bills. When my dentist kept offering "professional courtesy", I would say -- "thank you very much, but I can afford my bill, and I prefer to pay it. It might be better if you put the fee in a separate account to help someone who is indigent."
If you look at the "Hippocratic Oath" -- where I believe this whole thing started -- it isn't about giving away professional
services, but about controlling professional
information and training. It also binds the student to care for his teacher should he fall on hard times -- not just for professional services, but for all needs.
....
I will keep this Oath and this stipulation- to reckon him who taught me this Art equally dear to me as my parents, to share my substance with him, and relieve his necessities if required; to look upon his offspring in the same footing as my own brothers, and to teach them this art, if they shall wish to learn it, without fee or stipulation; and that by precept, lecture, and every other mode of instruction, I will impart a knowledge of the Art to my own sons, and those of my teachers, and to disciples bound by a stipulation and oath according to the law of medicine, but to none others.
...
http://classics.mit.edu/Hippocrates/hippooath.html
