I didn't say you did. I was trying to understand your point, and so was inferring what you could possibly have meant with your original comment.

Oh, sorry. I definitely think a father can (should?) celebrate medical advancements like this, and definitely shouldn't undermine death like "Ah, that's life". My point is that people often worry about their children's death when they themselves are still alive. Death seems okay if it's when they don't get to see it

Death of someone whose potential was largely realized is a very different thing than the death of someone who never got a chance at the same.

I would be deeply unhappy to learn that my children won't live to old age.

Also witnessing the death of a loved one is obviously traumatic. People grieve their parents dying of old age.