There are lots of threads about the level of connectivity between the generations and I am sure it is based on the family history.
Our parents were born in the 1920s and 30s. DH parents. never played with them throughout their childhood. He really had to be taught how to play with our kids and in their early years it took a while. He was bored by board and card games, found it really difficult to play imaginative games. Listening to him reading to them was torture. When his DPs visited they were very much onlookers.
My mum was the same, but my dad was brilliant. We were part of a huge extended family and every kid adored my dad.
We have 8 GCs and I saw the same in his interaction with them. He is a brilliant Granddad as he was Father. The way he is with the children and grandchildren is polar opposite to mine but they love him. I really believe they benefit from the different approaches.
I wonder if there is too much expectation on grandparents to behave in a particular way, and feel short changed it they do not.