It's got so bad, that today film makers won't do an animal story where the animal dies at the end. American movie-goers won't stand for it. We are all so deeply estranged from the facts of death. Blood is almost an embarrassment. Babies are born in hospital, old people die there.
Few people have to face the unpleasantness of killing their own hamburgers.
Death is no longer part of the cycle of life. Death is socially unacceptable. Everybody knows the hero can't die. Maybe this basic disbelief in the reality of death is part of the cause for terminal violence in the States. Less in the realm of speculation is a corroded attitude to the natural process of life in the wild.