Medical Failure

In the McMaster Textbook of Internal Medicine, the Chapter "Last Days and Hours" defines death:

"Death is defined as the irreversible loss of bodily functions that support a living organism. In the

majority of cases (when respiratory and circulatory functions are not artificially supported), the

traditional criteria of death apply.

The Traditional criteria are further explored: 

1) Cessation of circulatory function

2) Cessation of spontaneous respiratory function

3) Dilated pupils unresponsive to light

The Chapter defines death in very scientific ways- it is after all, intended as a textbook for physicians. But what it doesn't explore is the notion that death is - in most regards - failure of medicine. 

But medicine was never intended to provide the elixir of everlasting life. So why do we now treat the profession in this light?