Aye if the person cannot survive without a machine and can never be conscious of the world around them, then How can you call that life?
Without the machine they would die. LEt the person die, let nature take its course. When someone is braindead then we have helped the person as far as we can. Nature or God would take back the soul of that person, except by artificially keeping them alive, we rob them of that chance to move on.
We put down a pet when we cannot help them anymore and wish to end their suffering. We love them that much that we dont want them to suffer and leave this world in a slow agonising death.
Why can't everyone see that we offer the 'dignity' to our human loved ones? By keeping someone breathing and just breathing we are only fulfilling our own selfish needs to keep them with us. Even though it be a living corpse.
My grandmother was declared braindead after a massive stroke and she died 5 days after they disconnected the machine. She never woke up, never showed any indications of regaining brain activity. SO when she was ready, she left..... which happened to be just after when all her children had arrived and saw her.
She was on the machine for 2 weeks, and constantly deteriorated. So she was going downhill. Once my father and aunts were told this, and they saw the charts and everything, they readily agreed to it.