How are they not harmed?
It is most likely that all physicians are harmed by this legislation. It does not have to be that they end up unemployed.
It doesn’t work the way you think it should. It works the way it works.
http://legal-dictionary.thefreedictionary.com/standing
It is astronomically difficult for any plaintiff to achieve standing against the government, who, it is assumed by the court, has the magnanimous wisdom to pass laws that are universally beneficial. That is the way it is.