In a piece for Forbes earlier this year, Scott Mendelson took on the question of whether there are "too many comic book movies."
His answer was a firm "No," on the grounds that comic book-based superhero films are actually not that numerous, and that the misconception reflects (besides superhero films being a convenient target for those who dislike the prevalence of blockbusters) the disproportionate attention those relatively few films get, noting the things he chooses to write about (which include, of course, comic book superhero movies).
However, it cannot be denied that in recent years they have accounted for a very large share of its highest-profile and most widely seen films. In the thirteen years from 2002 to 2014, nine saw at least one superhero movie in their top five earners at the American box office. Every single year saw at least one superhero film in their top ten.
By contrast, we can go for years without a disaster movie or a space opera becoming a hit of that caliber--and often longer than that without any non-Star Wars, non-Star Trek, non-superhero related space operas becoming hits.1
Moreover, the superhero films that are either based on comics, or so similar to such heroes that one probably ought to count them (I have in mind movies like 2004's The Incredibles, and 2008's Hancock), have become markedly more prominent these past few years. The average was something like 1.5 such movies in the top ten, and 2.2 in the top twenty, from 2002 to 2011. The average has been about twice that in the years 2012-2014, with the last year having four superhero movies in its top ten grossers (Guardians of the Galaxy, Captain America: Winter Soldier, X-Men: Days of Future Past, Big Hero 6), and six in the top twenty (there were also The Amazing Spider-Man 2 and Teenage Mutant Ninja Turtles)--some thirty to forty percent of the whole year's biggest hits coming out of this one subgenre.
Twenty fifteen does not seem to be nearly so superhero-dominated, but we have already had Avengers 2 become the year's number two hit; and the years to come promise more of the same, with 2016 looking a lot more like 2014. Currently on the schedule are Deadpool in February; Batman v. Superman: The Dawn of Justice in March; Captain America: Civil War and X-Men: Apocalypse in May; Teenage Mutant Ninja Turtles: Half Shell in June; Suicide Squad in August; Doctor Strange in November; and I'm not even sure I got all of them. In 2017 we can expect, doubtless among others, more Wolverine, Guardians of the Galaxy, Spiderman and Thor from Marvel, and the Justice League and Wonder Woman films.
In 2017 we can also expect a Lego Batman movie--which may not altogether "count" by the standard given above, but it does testify to the phenomenon's broader cultural presence, as well as the fact that films which may not be strictly "superhero" in the sense of DC-Marvel product have also been a commensurately larger presence in film.
Consider just 2014. I did not include The LEGO Movie, despite its having its share of superheroes with Batman and company (while its hero Emmett Brickowski proved a superhero in his own right)--but had I done so, it would have weighed the assessment even more heavily in favor of superheroes, given that it was the #5 hit of the year. Additionally, appalling as this may seem to purists, to those who are non-fans other major hits like the Transformers and Divergent (#7 and #18, respectively) can look so much like superhero films (protagonists transcending the limitations of mere humans, fight scenes between beings of colossal, more-than-human power) as to be for all practical purposes simply more of the same.
At the same time, innumerable, smaller successes bolster the broader impression. To name but one, Scarlett Johansson, who plays Black Widow in the Marvel films, also played the super-powered Lucy in last year's film by that name (which, at #24 at the American box office, narrowly missed the top twenty, but did make the #18 spot on the global list), as a result of which she will be going on to play another superhero in the remake of Ghost in the Shell headed our way in 2017.
And so on and so forth.
In short, the superhero film has been a strong presence for rather a long time--stronger and longer, in fact, than any other action genre in decades. And in these last few years, it has enjoyed a really extraordinary share of the biggest hits at the multiplex, when defined narrowly (let alone loosely). Moreover, the slate of films being prepped for release are locking this state of affairs in for at least the next two years. Given these hard commercial facts, someone who thinks that superheroes have all but conquered the box office is not deluded, but at most a bit hyperbolic.
1. Why make that distinction? Because it shows the genre's presence is often less a matter of the field's vitality than the determined milking of old franchises, or tangential success.
My Posts on Superheroes