It's not really "just smartphones", that's too simplistic.
It's that entertainment has changed massively over the last 6-7 years.
7-8 years ago, Facebook was basically just starting. There was no Twitter/Instagram/etc.
If you wanted to watch a movie, you drove to your Blockbuster Video and rented 1 or 2 movies for the week. Netflix mailed you 2-3 movies at a time and that was the new thing.
Today, Netflix/Hulu/etc. give most people a full on video store at their finger tips at any time on top of dramatically expanded cable TV options and PPV ordering.
Having a TiVO was still a relative luxury 8 years ago for most households, today it's basically standard for any cable package, and having it gives you hundreds of hours of programming piled up.
Then you have smartphones and tablets on top of that. People just have way too many entertainment options.
Why invest 30+ hours into a single video game? There's too much to see/do/watch/read these days. Plus diminishing returns ... PS4/XB1/Wii U simply aren't as exciting as 360/PS3/Wii were when they were introduced. You can't reinvent the wheel every time, these are just iterative upgrades with similar types of games, nothing that's a paradigm shift.
