Maybe it's not generational at all, but rather people who have had to relocate many times in their life. The more stuff you have to carry around, the harder (and more expensive) it is to move. Many bookcases full of books is a lot more hassle to move than a hard drive full of ebooks.
This. I was in the same situation as the grandparent post - I couldn't think of a time when I could do without analogue media. However, I can see the advantage now that I've moved to London. I have to pay a fortune to rent a tiny flat and don't have the space for a large number of objects. Any CDs or DVDs I buy are transferred to disc and I take the physical media to my parents' house for storage. For books that I want to keep for the long-term, I've started to go for the paperback to reduce storage space, and regularly clear out those that I don't want anymore. It's impractical to drive in the city, so I have to think about how I will transfer items to a new place. I would love to own a 32-inch TV, but went for a 22-inch TV because it is easier to carry.
As the population grows and housing costs increase, it's likely we'll be forced to live in accommodation that is smaller than that held by our parents. I suspect we'll see more people moving to digital storage for many types of personal item to free up some space.