I think that it is horrible. Personally, I never want to fail in anything do, but I don't have that choice as an employee, father, husband, or frankly as a human being. If she cannot handle the heat, well, you get my point. Failure is a part of life. She has chosen a profession in life that has the highest failure rate, and if she cannot handle failure maybe she should choose another profession.
I think that it is fair for a doctor to generate a contract with any of her patients that says if we cannot work together and you do not follow my instructions, then we can part ways. But to say we do not accept specific patients, that is just plain rude.