My ex thought the only way to get llama wool was to kill the llama. For some reason, this logic only applied to llamas, she understood sheep wool didn't require the same sort of blood sacrifice.
Natural lifespan? What natural life span? Sleep are unable to survive in the wild for more then a few years before the amount of wool they grow will cause their bodies to cook themselves. They are dependent on humans sheering them to live out their "natural" lifespan. Ultimately they, along with all animals we have breed for service are not natural any more.