Specifically, the problem is the visual and rhythmic sameness of the films' execution.

Generous critics and viewers point to fleeting moments of personality, such as the flirtation scenes in the recent "Amazing Spider-Man" movies, and the improv-flavored conversations in the "Iron Man" films, and Joss Whedon's very Whedon-y quips in "The Avengers" ("You really have got a lid on it, haven't you? What's your secret? Mellow jazz? Bongo drums? Huge bag of weed?"). But these defenses sound desperate when you look at the films as whole objects. Despite their fleeting moments of specialness, "The Avengers," the "Iron Man" and "Thor" and "Captain America" films, the new "Spider-Man" series and "Man of Steel" treat viewers not to variations of the same situations (which is fine and dandy; every zombie film has zombies, and ninety percent of all westerns end in gunfights) but to variations of the same situations that feel as though they were designed, choreographed, shot, edited and composited by the same second units and special effects houses, using the same software, under the same conditions. As long as people are talking, there's a chance the movies will be good. When the action starts, the films become less special.

Shots of people fighting inside and atop collapsing and burning structures all feel basically the same, though if you're lucky the filmmakers toss in an emotionally resonant moment, such as the hand-to-hand climax of "Captain America: The Winter Soldier." Sometimes the camera shakes a little, sometimes a lot. Giant creatures roar and stomp in more or less the same way, across CGI'd landscapes rendered in more or less the same way, unless the threat is Earth-made, as in the two "Captain America" films, in which case it's helicarriers rather than alien starships that catch fire and crash into buildings. At some point somebody straps on power armor or climbs inside a robot. Machines bash other machines for a while. The bashing is choreographed and shot and edited pretty much as you expect, with few aesthetic surprises. You hear metal groaning and rubble crashing to earth. Walls crumble, craters open, bridges collapse. Spider-Man skydives into the Manhattan grid, Thor whooshes hither and yon, Iron Man plummets from in the ionosophere and is saved by The Hulk, and somehow none of it has the visceral or dramatic weight that it should. The smaller an action scene is, the better the chance that it'll be genuinely exciting (the elevator dustup in the new "Captain America" is the best recent example). The bigger the canvas, the more boringly typical the action becomes. Boring action makes hash of any character beats that the filmmakers and actors went to the trouble of setting up.

Even if you generally enjoy these movies, you know you can visit the concession stand during the scenes of heroes being heroic and villains being villainous and not miss anything. If there's burning/exploding/punching/collapsing/roaring/stomping in a scene, you're free to get popcorn or call home. The good stuff is CGI-lite, or CGI free. Think of Cap just-friends-flirting with Black Widow or visiting a meeting for traumatized veterans in the second "Captain America," or Andrew Garfield, one of the great screen criers, tearing up as Peter Parker contemplates his late parents or remembers a line from his sweetheart's valedictory address or tells his Aunt May "I'm your boy, you're my everything." As a friend observed, the gap in artistic quality between the intimate human interactions and the large-scale action sequences in recent superhero flicks is so immense that they seem to have been made at different studios by different directors obeying different marching orders. The "ground rules" scene between Peter and Gwen in the new "Spider-Man" feels so sweetly alive—so much like a conversation that actual young lovers might have—that when you get to the end of this overstuffed and overlong blockbuster and have to suffer through yet another tediously unoriginal confrontation between Spidey and two, count 'em two, supervillains, then a climax that extorts cathartic tears instead of earning them, the effect is disorienting in the worst way.