I don't think anyone should be excluded from death watch and age shouldn't factor at all. I think there's something to be said about people's fear of death and how Western culture stigmatizes it. Other cultures have treated death very differently; tribes in the New Guinea famously ate their loved ones, while others brought relative's bodies out on holidays to eat with them at feasts. Yes, it can be painful losing a friend or relative, but it's natural and inevitable. While I don't endorse cannibalism or holding onto bodies, our extreme aversion to death and the dying borders on emotionally unhealthy and dictates that death is a traumatizing experience to be avoided at all costs.
The following is anecdotal, but was a primary influence on my view. When I was three my brother died. My parent's initially thought this would be too damaging for me to cope with and didn't allow me to visit him after his accident or attend his funeral. While I struggled with why he disappeared this did some serious, but temporary, damage that manifested into emotional issues and a severe stutter. About a year later they took the time to explain why he was gone and the concept of death, this was a powerful moment that I still remember vividly -- everything made sense. The other issues resolved themselves, but what I learned was that it wasn't death that was traumatizing, but how everyone regarded it.