Because between us and they have gap about generation 
In fact, older people always have a lot of worries and I do not think they are interested in investing in Crypto because they are afraid because Crypto is so new and it's like a virtual thing, they can not see it and can not handle it. In addition, Bitcoin have a huge risk and it is not valued by any model and fears that this is a psychological game.
I have met many old people and I told them about Bitcoin, as a result I was scolded for daring to believe what the internet said, oh my gods @@
In fact, the idea of trying to cope with the way technology is moving pretty fast is something huge for them which I believe their brain may not actually be ready to go through all those stress of trying to blend with the jet age. In fact, older people always have a lot of worries and I do not think they are interested in investing in Crypto because they are afraid because Crypto is so new and it's like a virtual thing, they can not see it and can not handle it. In addition, Bitcoin have a huge risk and it is not valued by any model and fears that this is a psychological game.
I have met many old people and I told them about Bitcoin, as a result I was scolded for daring to believe what the internet said, oh my gods @@
This new age is moving very fast and I imagine how things are going to be when we also start becoming an older generation as well. It is normal, as they would rather want to stick with what they have believed in and has never failed them over the years. I believe it is just the truth that they feel more secured investing in what they have always believed in when it comes to store of value.
Like OP said, they are older generations, and we know how this age is evolving pretty fast which I want to assume will be so much for their brains to even start wrapping how things are done. Also, these are less risky investments, and no old generation will actually want to be taking unnecessary risks at their age anyway.