Yes, it is less of a tragedy when an old person dies. Old people have less of their life to lose and have less remaining potential to contribute to society. The death of children is always more tragic than the death of elderly people.

This isn't a perspective exclusive to young people either. Last year my grandfather died and my cousin had a miscarriage. My grandmother was far more distraught over the latter because she understood that her husband, who she'd loved for nearly 60 years, had already lived a full happy life. She said as much explicitly.