The problem with parents who do not vaccinate their children is two-fold: they don't have a grasp of the facts (education) and IQ. Parents with limited mental capacities make poor decisions. Why should we expect the medical community to shoulder the responsibility to protect their clientele from people who have little regard for others? The answer here is simple. Let parents of unvaccinated children search for a doc who will serve them.
While I completely understand the desire to drive home the point to parents that not vaccinating their kids is medically misguided and irresponsible, the patient here is the minor themselves, who does not have a voice in this decision and deserves medical care. Doctors have an greater opportunity to guide these parents to vaccination with them in the office, not out of it.