My parents are in their early 60s, physically fit, and live 2 hours away. My kids are their only grandchildren.
We used to visit them fairly regularly and stay in their huge house, but my mother resented my children allegedly "messing up her house", and eventually had a tantrum about some scatter cushions being repositioned, and the toddler crawling towards the (cold) living flame gas fire and attempting to take a piece of fake coal off it, while I was trying to do our packing in the bedroom upstairs. (At the time my father was in the same room as the toddler, watching a dustbin lorry out the window with interest, but ignoring the toddler). She said I should have been watching the toddler at all times, as I was its mother.
They have a standing invitation to come over here, but this resulted in one occasion when my mother took offence at something negligible the children did while I was at work. Neither I or my father really understand what it was (he was there at the time, but didn't think they were doing anything usual or wrong). I came home to find her with a face like thunder and her arms folded, sitting at the kitchen table, demanding to be taken home by my father, as she had "had enough of it all".
They now see the children for lunch at our house 2 or 3 times a year, leaving after a couple of hours to go to the garden centre and drive home. When they are here, they mainly talk to us rather than the children. They spend their Christmases with childless couples or on holiday overseas.
I am a bit perplexed by the whole situation as my FIL is in his 80s and yet spends a lot more time with his grandchildren, doing the school run, taking them out and so on. He really enjoys their company and they are good as gold with him. The children find it all a bit hurtful and keep asking what they have done wrong. DH finds it totally baffling and is quite cross about it.
I can only assume my mother is being a bit of a self-centred toddler herself, yet has lost the knack of being with younger people.