We all know that we will inevitably get old (assuming nothing even worse happens first). Getting old leads to reduced physical and mental abilities, and is generally perceived as a negative. But because our society has accepted it as inevitable, we become acculturated to accepting it. To deal with it even better, we develop excuses for why it is a good thing. It prevents overpopulation. It makes room for young people with new ideas. Life would get boring after a hundred years. Etc.
What does this say about us?