Ken's article is an interesting one, and I agree with the points he makes. My own Advance Health Care Directive reflects this.
As a practical matter, should you or your loved one find yourself in a U.S. hospital and want to have your wishes in this area followed, it's important that you make your wishes known often and emphatically. Better yet, make sure you have an advocate, and that that person be able to vigorously make your wishes known. Hospitals are immensely powerful entities, and once within their clutches many forces come into play.
European hospitals operate somewhat differently. Many countries realize that health care expenses are not infinite, something U.S. society is not ready to recognize yet.