Some people like being grandparents (and aunties and uncles) at arms length. Annoying but, meh, what can you do about it.
My DH is adamant his DPs adore being grandparents and doing things with our DSs when they visit and stay with us, as do his siblings and truly thinks they are hands on, but I just don't see it.
They come over, see them over breakfast and talk to them, take walks on their own without the GC, look at any art work they may have done, but not join in, etc. Have a pre-dinner drink on their own in the lounge while I feedthe DC, say goodnight and have a kiss and a cuddle before bed. They really aren't hands on at all.
In fact my DH said to me before their last visit that his DM hadn't ever bathed the boys and she would really like to. His DM is very forthright, and doesn't hold back, if she wants to do something she will do it, if she wants you to know something she will say it. I just said 'if your DM wants to bathe the boys, she is more than welcome, but there is no way I will be asking for her to do that unless I absolutely need to'. The only time they have offered to babysit the boys is for us to go out locally AFTER the boys were already in bed and asleep.
In other ways, they're great. They always remember special occasions, they skype frequently, they offer advice to me when asked rather than foisting it onto me which makes me more willing to actually ask DMIL's advice than I otherwise would (unless they REALLY think I'm doing something wrong then would say something). Just.... hands off.