There's the contradiction. One person's freedom of action in the use of his values is preventing another from enjoying the same. It is up to him to decide under what conditions he will offer them for voluntary exchange with other people, that is, his customers, his patients, in return for their values, that is, their money. It would sound ludicrous if a doctor demanded and forced people to become his patients, if he forced them to pay for his services whether wanted or not, to make other people or the government provide him with his livelihood. It is just as wrong for a patient or the government to force a doctor to treat any person or group of persons regardless of his own wishes.
Voluntary interactions are the only moral way to provide for an exchange of values.
Unfortunately, doctors do frequently advocate for others what they abhor for themselves. When the government then creates new regulations limiting what doctors may or may not do medically, what they may or may not charge their patients, where they may or may not work, when more and heavier chains are forged to weigh them down, they will have no one to blame but themselves. The whip they'll hear cracking as they are forced to toe the government mandated line will be wielded by the very master they once considered their servant. It is vitally important in this struggle that those most affected by the heavy hand of the State do not concede to their opponents the very moral principles they require to restore and then maintain the freedom they need to practice their profession. There are no such things as patient rights any more than there are doctor rights or women, gay, student, disabled or any other supposed kind of group rights.