Doctor does something you don't like that harms no one. You want the gov'ment to come in and tell the doctor what he can and cannot say. That is wrong as the government has no moral right to do that - the doctor and the patient are not the government's property.
The doctor by accepting the license accepts the fact that the state can regulate what he does when acting in the licensed profession. He is of course free to find another job that is not licensed.