I think part of professionalization would include your professional organization having come up with a set of standards for password handling that must be followed under penalty of professional sanction, having those available online and in printed form, and having courses that programmers could take to help them work under those guidelines efficiently.

Programming seems like a job particularly suited for professionalization, simply because programmers have to constantly be learning new things, and that's a thing your local org could provide to keep the lights on rather than relying completely on dues payments. If they were a blanket organization, they could even control supply through raising standards, and could certainly detect wage-fixing collusion easier than individuals.

Having clear guidelines and a place to find instruction that supports those guidelines makes "If you think you know what you're doing but don't?" a pure ethical problem. You either checked or you didn't.

Maybe look to the National Association of Realtors for a framework.