text: The nature of death in general is an important and little understood issue; I am glad you brought it up.
  
  For every living creature, its death is a natural evil. Such death is a systemic evil too, since the life shared by all creatures cannot be sustained without the constant cycle of death. From another point of view, or another measure, as you say, the dying of older creatures is a "good" thing, leaving space and resources for younger ones. But it remains true that in itself, death is an evil.
  
  Killing too is always an evil, even in circumstances when it is justifiable or excusable. And one of the most horrid of the systemic evils that humans must face is having to feed on the tissue of other living creatures for survival. We can at least mitigate that by feeding only on the non-sentient.
  
  Many wisdom traditions, e.g. Christianity, teach that our own personal death is not to be feared -- and that is true too. But it does not justify imposing our beliefs on the dying of others.