Its actually very simple. Its because the movies are good and quality of them improved greatly with marvel studios. I dont need to defend this statement either, any review source one prefers will show that Marvel studios has the best ratio of well received and critically acclaimed movies than any studio. Around 20 movies and almost 18 of them are favorably reviewed is unprecedented. I dont see them because they are superhero movies. I see them because they are good.
People like seeing good action movies. Thats why they are popular. They dont need to have attachment to the source material anymore. Pre 2008 these movies were expected to be bad and any that were good turned heads. Now its the opposite, they are so good, when bad ones are made it becomes a huge story.
No one has to like them though. They put my wife to sleep. Then again Im watching my third episode in a row of real housewives right now...
Good is both subjective and open for debate.
Lots of people like these movies and will continue to see them.
The genre makes up about half the movies families with younger kids can actually watch together, so there arent many choices to begin with.
I saw Civil War, Spider-Man Homecoming, Ant man, Deadpool, Guardians 1&2, Wonder Woman, and a couple of the Iron Man movies.
I was entertained at times, but I lost interest in the never ending CGI fighting pretty quickly.
The last few movies, I literally couldnt wait for them to end. I just wanted to get outta there.
My 10 yr old son will watch them over and over again.