Long story short, superhero movies will stay...for now.
According to a report by Vasily Karasyov, the Senior Media, Cable, and Entertainment Analyst at the Susquehanna Financial Group, Hollywood should brace for the decline of the superhero genre. Karasyov reported that the genre in the film industry has particulary been a box-office success for many studios, but will spiral downward in the next several years.
The entertainment expert also reported a bit of the history of the current era of superhero movies that began in early 2000 because of CGI (Computer Generated Imagery) becoming a lot more popular and it was easier to make movies with CGI. Also is noted is that there are only four franchises that have been successful at the box-office in the past decade: Spiderman, Batman, X-Men, and Iron Man. Of course, there were a whole bunch of superhero movies besides these franchises (such as The Punisher, Daredevil, Hulk, Superman Returns, and several more), but they were not necessarily successful or warrented a sequel (Hulk was rebooted, but still didn't get the big money, future Daredevil and The Punisher projects are shelved and Superman is being rebooted).