There are people shut as quadriplegics who required full time and expensive daily care but who still want to live and some of them even manage to hold jobs. Mental state can make a huge difference. For awhile we even had a poster here who was in a locked-in state, his AMA thread was very interesting. Regrettably, he is no longer with us.
Other people, of course, would not want to exist in such a state. YMMV.