”You aren't the arbiter of others grief.”
That is a wild and inaccurate generalisation @Pashal2 - I think it is perfectly reasonable, for example, to judge someone who rings up the widow of someone who has just died, and spend ages weeping and wailing on the phone, making it all about themselves without thinking about the feelings of the widow, or someone who announces a death on social media when it is definitely NOT your right or responsibility to do so, and when doing so means that people who were much closer than you to the deceased have to learn of their death on FaceBook or whatever, rather than being told in person.
I am not disputing the fact that people can and often are deeply moved by someone’s death - but you simply cannot be so selfish in your grief that you give their closest relatives and friends more grief and pain.
I have seen it described in terms of concentric circles. In the middle is the person who has died. The next circle out is most often their closest family - parents, spouse and children, then another circle comprising wider family and close friends, another that is less close friends, close work colleagues etc. Basically, the rule is that you should offer help and support inwards, and should expect help and support from further out. So, if a child dies, no-one should be depending on the child’s parents for support apart from their other children. Even grandparents are slightly further out in the circles, so should not be putting their grief and needs above those of the parents and other children. I hope this makes sense.
This doesn’t mean that there can’t be support flowing outwards, but it does mean that, if you are making your grief out to be soooo much greater and more important than the deceased person’s wife/child/parent and you are making them bear the burden of your grief instead of supporting them, you are being selfish and a grief thief, and I will judge that sort of selfish behaviour.