You are medically incorrect. Babies in the NICU for example are frequently on ventilation support and are very much alive and indeed are weaned off of ventilation to go home with their families to lead full and normal lives.
Many people who are ventilated recover. Brain death and cardiovascular status are much better prognostic indicators, and even then there are people who inexplicably recover. It is a very dangerous thing to judge the quality of another human being’s life.
I would never presume to second guess the tough decisions made by families in this circumstance.
My husband is a case in point. In July of last year, at the age of 62, he had an emergency appendectomy. The doctors expected him to be able to go home in a day or two, but, due to his lack of honesty about his history of smoking and his use of alcohol, the doctors did not have all the information they needed to determine the best type or the appropriate amount of anesthesia to use. They did do a pre-op chest X-ray, but they did not have time to look at it before he went to the OR since his appendix was about to rupture. They were surprised that it was taking him so long to wake up after the surgery and that he was not oxygenating well. They put him on a ventilator to help him breathe and he remained on it for over a week until they were able to wean him off. Without it, he would have died from a "simple" appendectomy. He is perfectly fine now and his blood oxygen levels are better than they were before the surgery.