Here's the thing so many people miss on a number of e-issues, and you come close to hitting it. The MEDIUM changes how people interact with the content of the media. More specifically, eye scan patterns, how people read content, and a lot more are different across different media, and in particular print vs. e-reading. It's even going to be different from one e-device (let's say e-ink) and reading on a monitor.
So, it's not just an issue of preference, or age, or anything like that. When you change the experience of dealing with the content, you change how people assimilate that content. Even more to this, there's some evidence that suggests that content served via Internet/Social coupled with the fact some people have stopped reading print, actually changes brain structure for those people, and in negative ways -- brain plasticity.
One unfortunate thing about the technos and thinking about techno solutions, is that where the rubber meets the road is at the nexus point between human and machine, and very few people who push the technology as fixer upper have any clue about human information processing. And of course, that's why we get such bad e-learning, and a range of bad stuff, that "should" work, that is so long as you pretend human cognition and emotion doesn't come into play.
Same for social media. It's never worked the way so many people think it "should", because it doesn't fill the human needs its supposed to fill. It's kind of obvious.