Humans don't have a self-preservation instinct. Instead, like all life, they properly have a reproductive instinct. We only have self-preservation instincts as far as is necessary to make reproduction possible. In an age where many are deliberately "child free" it might start to look as if terror management is the name of the game, but that's just an artifact of a bunch of other neuroses that have taken hold.

I need to die so that there's room for my grandchildren and great-grandchildren.