To me, it speaks to a kind of insecurity. Like these people are embarrassed by the fact that they like schlock, and so they have to try to make up insane justifications for watching it.
I like kiddie shlock like GI Joe and Episode 1: The Phantom Menace, and I don't need to make an excuse for it.
No, guys, superhero movies are not the modern equivalent to Shakespearean tragedy or Greek mythology, and you don't have to pretend like they are in order to enjoy them.
The thing is, some superhero movies could qualify as that. Certainly movies that have a tragedy or a lesson to them could be the next Shakespeare or high art. I'd consider the Tim Burton Batman movies, Revenge of the Sith, or the Watchmen as a sort of modern tragedy in the same style as the tragedies of Shakespeare or the Greek myths. Some movies like the Avengers, the Phantom Menace, and Guardians of the Galaxy are just childish fun, but some like the Dark Knight Trilogy can be just as dark and poignant as past classical literature.
Not only are they not the modern equivalent of the classics, not only do they not need to be, but trying to make capeshit into this weird version of ancient myth that bends the knee to modern identity politics has this funny tendency to destroy any hint of archetypical storytelling and replace it with bad political takes, paint-by-numbers snark, and blatant pandering.
To be fair, enough of the classics were made to pander to the political elite of their time. The Aneid was made as a way for the Romans to one-up the Greeks, some of Shakespeare's plays have the English as the good guys like in Macbeth, and the Greek classics were made to show how obeying the gods and doing your patriotic duty is the right thing to do.
It's just that they did a far better job of it than modern, politically-correct crap does. Especially when a lot of it just comes naturally-loving your family, fighting for your loved ones, your country, your friends, your gods, it wasn't as artificial as telling you that hanging onto religion or guns is wrong.
I respectfully disagree insofar as Shakespeare's plays were considered low brow in their day and did not become high art until at the 18th century. Similarly, there is an argument that the superhero genre is a modern manifestation of hero myths that existed since before the written word. Take Superman as an example. It's hard to deny that Jerry Siegel took some inspiration from the tales of Moses and Samson from the Old Testament. One book I read nearly a decade ago also cited the swashbuckling action films of the time were also an inspiration as was the murder of his father.
And I would even say that some superhero/action films that take things seriously can indeed be our answer to the Shakespearean and Greek plays. Especially ones with great, sprawling worlds like say, Star Wars, or those that have a moral to teach, like the Sam Raimi Spider Man films or the Dark Knight trilogy. Each had a lesson to preach. In fact, the movie trilogies of the late 90s and early 2000s had moral lessons to go along with the action.
Star Wars Prequels: Perception isn't always reality, don't be so quick to trust the government with more power, don't think with your dick.
Sam Raimi Spider Man Trilogy: With great power comes great responsibility; you can't just act like a prick because you have power over others.
Dark Knight Trilogy: You must hang on to hope even in the darkest of times. (Revenge of the Sith's ending has the same theme)
As
@Lasersuit Larry said, capeshit doesn't need to equivalent to the classics. Will they be? Time will ultimately be the judge of that. Frankly, Bob's attempts to elevate it are--frankly--embarrassing to me as a longtime fan of superheroes.
It also embarrasses me because I did love past superhero films. But the modern MCU, as I've said before, is the equivalent of just Smash Bros. with Marvel characters that aren't as cool, interesting, or cute as the Nintendo cast.
It also speaks to their intellectual laziness because part of the reason why I pursued a BA in English was to understand the mechanics of storytelling from intellectuals like Joseph Campbell and Northrop Frye. Given Bob and his cohorts's lack of self-awareness and curiosity, I doubt they will ever understand what makes for a good story.
To them, what makes a good story is what makes them feel good. That's all it takes.