Playing God and selfishly preserving a life?

I'm sure you've heard about the 18month old in Canada who is in a persistent vegetative state and kept alive by ventilator and feeding tubes. Canadian authorities won't release him to be taken to the US for continued care, essentially dooming him to the end of his life there at the hospital. We saw the same thing with Terri Schiavo, Karen Anne Quinlan, and others.

Obviously these tragic situations present difficult ethical, moral, and social questions. Here's my take:

In a persistent vegetative state, it is my understanding that only the primitive brain stem is functioning. There is no self-awareness or consciousness. The expressions, movements, and reactions to stimuli that family members report as proof of consciousness are simply rudimentary and coincidental movements associated with artificial life preservation. This means to me that keeping this person "alive", if you can call that existence life, serves only to provide a focal point for the family to direct their love and attendance. I contend that introducing in the first place, life-support tubes, is playing God rather than removing them is playing God. When all hope of recovery is lost, no humans body should be kept artificially alive for the pleasure of a family who cannot bring themselves to let go.

A dignified death is the least we should be able to expect from our loved ones.