What it's about
It is about not wasting money and resources on resuscitating a patient the PATIENT does not want that. It's about taking the decision out of the hands of doctors or government and putting it where it belongs, in the hands of the PATIENT. If the doctor sees the patient is terminal and there is an advance directive, the doctor KNOWS and does not have to agonize over whether to save the patient's life or not. The doctor will usually err on the side of saving lives because 1. it's his job to save lives and 2. he doesn't want to get sued. An advance directive solves that dilemma.