I think you underestimate the power of denial, as I did before I read Sherwin Nuland's book, How We Die. In a lot of terminal cases, neither the patient nor the patient's family know that the case is hopeless, because the doctors don't want to break the news, and may not have accepted it themselves, since doctors often tend to regard saving the patient's life as a matter of success and failure and will try nearly anything not to fail. There are clear-cut cases, but most people die in cases where the probability of recovery is very low but not zero.