You've got THAT right! Hear, hear.
t'aint that easy.
Living Wills have also been used to deny care to people.
Are you being targeted for euthanasia? (Schiavo case only the tip of the iceberg)
That is their general function, to counter what used to be nearly unanimous bias in favor of life on the parts of the medical and legal communities. The default used to be to provide care (i.e., "patient's best interest is to live").
Those biases are changing too.