I recently watched Willem Dafoe in "Inside" and while it's not really a cinematic experience that could be called pleasant, I was actually satisfied at the end of it because it actually felt creative.
A friend of mine gets pissed off when I fall asleep in front of half the movies, he asks me to watch, but the reality is that those movies are bargain bin low quality comedies (or worse, documentaries) and its better use of my time to sleep than bother with it. It's actually one of my sleeping strategies, to empty my brain of thoughts, so...
I don't think there is a major problem with attention, neither in children or adults; it's just that it's a lot harder to sort through what is worth your attention and after some willpower is spent to choose something it doesn't get overthrown because of the psychology of commitment. But it is not worth paying attention, so people use whatever is around them to not completely waste time.
In my opinion inattentive children in classrooms has a lot more to do with teachers being bad and lack of physical activities than a problem with the kids. But teachers are politically untouchable nowadays and you can't ask them to actually be competitive or get fired. The pay is also progressive and equal regardless of actual performance, so you get terrible people who cannot keep kids' attention because they suck; but then we blame the kids. Sure.
Im of the opinion that the quality of content is hot garbage on a good day and actual entertainment is rare now.