Professionalism does not automatically equal ethical behaviour. Somehow, society has conflated the two: ethics and professionals - professionals are better (superior) human beings.
The pocket Oxford English Dictionary indicates: "professionalism" is "the ability or skill expected of a professional."
This dictionary defines a professional as: "
1 relating to or belonging to a profession.
2 engaged in an activity as a paid job rather than as an amateur:
3 competent.
1 a professional person.
2 a person who is very skilled in a particular activity."
Nothing said about ethics. Something that one would hope professionals have and use in working with more vulnerable people, e.g. patients. Unfortunately, not always the case.