Mine's a slightly different take on this but my son is now in his 30's....I split from his father when I was expecting him and it was a very bitter parting.
He has never seen his son, contributed towards his upbringing, sent a card - nothing at all.
I contacted his parents and explained that despite the situation with him, I'd be really happy for them to see/have some involvement with their grandchild.
The response was to ignore me and any overture I made.
Many years have past and likewise, all of my feelings of pain, hurt, anger and bitterness etc have passed too.
My son is a wonderful man and it's their loss BUT I know he's felt it over the years and in my opinion, it's his feelings and the feelings of every other child in this situation we should be thinking about.
I do wonder if these people ever think about that?