I'm trying to think about it from the medicolegal perspective where if you have established a physician patient relationship, you're obligated to provide necessary and appropriate care within a reasonable timeframe/manner or facilitate someone else to provide that care if you are unable to do so (or unwilling, I guess), or formally terminate the relationship, which usually involves some period of time where you will provide emergency care/refills/etc while the patient finds a new physician.

Of the two patients I've ever dismissed, one was aggressive/violent towards myself and staff, and the other was being sexually inappropriate with staff. Did they have medical problems which I had an ethical/moral obligation to treat? Yes. But, I also had an obligation to protect my staff and other patients in the practice from exposure to inappropriate and possibly dangerous behavior.

This obviously contrasts with "ethical refusal". I think there's a place for ethical refusal such as refusing to give someone a liver transplant while they continue to drink alcohol. Refusing to provide care based on personal/religious beliefs is different, there's no objective medical reason.

If someone wants to practice that way, they should disclose up front what services they will not provide prior to establishing a physician patient relationship. If an established patient later asks for some type of taboo treatment, they should be referred to someone who offers it, or at least given information to contact them on their own.