This critique of superhero movies is interesting, but it conflates two different points:
First, the quality of the average superhero/comic book/genre movie is declining. This is not surprising. If the law of large numbers holds anywhere, it should be here: given that the movie business is increasingly driven by small numbers of very expensive movies, a fair number of those movies should be of middling quality, and they are.
The decline in quality is not a surprise. Genre movie fans have traditionally survived on sub-par product. What is the old "Even numbered Star Trek movies are good, odd numbered Star Trek movies are bad" if not an admission that 50% of the canonical, flagship material is terrible? Given high stakes and a veritable farm of excellent writers, directors, producers, etc, the lack of quality control is astounding. No one in their right mind will defend the third X-Men movie, or Daredevil, or Catwoman, or the mid-90s Batman movies. The movies continue to get made because the movies will be seen regardless of quality. If someone messes up a franchise too badly, the powers that be wait a few years and hand the project off to someone else, which is how three different actors played the Hulk over fewer than ten years.
Variations on an origin story are not new. The idea that problems with plot or execution can be handled by simply disregarding the material that came before is a staple of the very comic book and superhero narrative universes the stories are drawn from in the first place. This is the reason for so many origin stories: having to erase the previous generation's hold on the narrative arc. Trying to keep continuity within a messy world and tell an interesting story is much too complicated for the average writer. Admitting that the most interesting stories have already been told (or can't be told in a movie) is not an option for the people who make the films. From the audience's perspective, and from the filmmaker's perspective, better a middling piece of narrative than none at all.
Second, the problem with superhero movies isn't their origin stories: the origin is usually their only unique element. Superhero stories are burdened with superheroes, people for whom most narrative content is ruled out. A movie in this genre has to have an adventure of some kind, and an antagonist, and it must affirm the moral order of the universe. Batman might be a person of dubious virtue in the Nolan Batman movies, but he's obviously better than the Joker or Bane. The fix is in from the beginning: there's no way he won't win. Consequently, there are no stakes. Batman will win, so it's just a question of how. That film can be clever, but it can't be interesting.
Superheroes also cannot have the ennui that an average person has, the kind that provides the grist for a number of narratives. An average person has to grapple with the question of meaning and the question of vocation: what am I supposed to do with my life? From this one gets both the angst of the young and the uncertainties of advancing age. The superhero is faced with a question that is similar but lacks any frisson: should I accept my vocation or reject it? But the question is a dishonest one, because the hero will always accept it, even if late in the story: otherwise, there's no movie. Wolverine will never just walk away.
These films can't do mundane things for 90 minutes, or 150: there will never be a Tony Stark-Pepper Potts Before Midnight.* The movie studios wouldn't want it, audiences wouldn't want it. And it's not clear it would even be a superhero movie without the villains and the adventure. That's the catch. A superhero movie that stays within a comic book world will be some variation on beginning-threat-response. A superhero movie that attempts to move outside that becomes just a movie, and has to contend with the very best in those other genres.
*I suspect, for what it's worth, that the Stark-Potts banter is the equivalent of Itchy & Scratchy cartoons in the Simpsons: the sort of thing the writers are only capable of doing in 20-second bursts. At that length, it looks like a take on screwball comedy. At five minutes, they'd have run out of clever-ish things to say.