A lot of missing context here. "Star Wars 8" has not been released, so if you're drawing effect of 7 on 8's performance, I'm not sure how you're doing it. Budget alone does not necessarily tell you expected gross.
Perhaps you were talking about Rogue One? There's a lot of context there that would temper any direct comparisons.
https://en.wikipedia.org/wiki/List_of_Star_Wars_films_and_te...
"The Clone Wars", "Rogue One" are both on this list. http://www.the-numbers.com/movies/franchise/Star-Wars#tab=su... So 8 is "Star Wars Ep. VII: The Force Awakens" and 9 is "Rogue One: A Star Wars Story"
Ignoring https://en.wikipedia.org/wiki/Star_Wars_Holiday_Special which was never in theaters.
So, yes revenue was down, but the movies where also very derivative. The top grossing films adjusted for inflation are Gone with the Wind, Avatar, the first Star Wars, Titanic, The Sound of Music, E.T. the Extra-Terrestrial, The Ten Commandments, Doctor Zhivago, Jaws, Snow White and the Seven Dwarfs.
The Force Awakens might make #10 on that list while being the only franchise movie to do so. But, no movie from 2016 is even close.
And you can't discount franchises, kids movies, whatever. Tastes change. One decade people want high flying, heavy-action westerns. The next they want gritty, brooding introspective crime dramas. Then fantastic/sci-fi movies. Public tastes change, and you can see that all over the history of the cinema.
No doubt that consumption patterns have changed, almost assuredly due to the glut of options available at home + technological improvements that have improved the quality of home viewing. I think it not unreasonable to suggest that Hollywood is splintering between the theatre and the home theatre at this time. Measuring ticket sales is a pretty shallow & simplistic way to measure the health of huge entertainment conglomerates.
Every movie has some people that like it, but mass appeal takes more. Shrek I is rare, but this year had 15 significant misses and no big wins.
http://www.the-numbers.com/market/2016/top-grossing-movies
Just looking domestically we have Finding Dory (squeal), Rogue One (franchise), Captain America: Civil War (squeal), The Secret Life of Pets (kids movie), The Jungle Book (kids movie), Deadpool (franchise), Zootopia (kids movie), Batman v Superman: Dawn of Justice (franchise), Suicide Squad (franchise), Doctor Strange (franchise), Moana (kids movie) etc. Down at #14 The Revenant was at least nominally an original movie, though very similar to several other films.
I don't think any of these where bad for what they where, but there was nothing new for the 14-40 group. 2015 had #6 American Sniper, #9 The Martian, but was again mostly rehashed movies until #17.