One of Hollywood’s favorite buzz phrases at the moment is “shared universe,” which rose to popularity a few years ago when Marvel Studios kicked off its own with The Avengers. The movie, which brought Iron Man, Captain America, Thor, and other heroes together is still one of the highest grossing films of all time. In the years since, other studios have pushed to create their own shared universes (that may not necessarily involve superheroes). However, although Marvel has continued to build its Avengers universe, even expanding beyond the core group of heroes with James Gunn’s Guardians of the Galaxy, some studios haven’t seen success with their respective shared universes.

Most notoriously, Sony’s rebooted Spider-Man franchise is still in the middle of reworking its plan following the poor reception to this summer’s Amazing Spider-Man 2. Now, Gunn, who will work with Marvel again on Guardians of the Galaxy 2, has weighed in on the shared universe push in Hollywood.

In a Facebook post titled “Carts Before Horses & Hollywood’s New Love of Shared Universes,” Gunn voiced his concerns over studios looking at the big picture of a shared universe plan and allowing the quality of a single movie to fall by the wayside. Though Gunn doesn’t criticize any studio or franchise in particular, he does praise Marvel Studios head Kevin Feige, Jon Favreau (Iron Man), and George Lucas for their ability to create good standalone movies that can lead to something more.

Read Gunn’s full post:

“Listen, I love big ass shared universes in movies, as well as huge franchises. But I’m a little worried about the numerous shared universes being planned by the studios, without having a strong base film to grow from – or in some cases, NO base film to grow from. Star Wars had the original Star Wars, the Marvel Universe had the original Iron Man, the Dark Knight series had Batman Begins, even movies like Transformers and Twilight – these were movies audiences loved, and the audiences demanded more from these characters. But these days studios are trying to grow trees without a strong seed. Execs and producers and sometimes even directors are focused on the big picture, without perfecting the task directly in front of them – making a great movie. And studios are trying to grow franchises from non-existent films or middling successes. It’s like they aren’t taking audiences into account at all anymore.

I know George Lucas, Kevin Feige, John [sic] Favreau, etc, had ideas where their films would potentially lead in the face of success. But I don’t think it ever got in the way of making that first movie count as if it was the last, of making it something wonderful that people would love whether it led to other films or not.

In short, I think this new business model is flawed. I think filmmakers and studios should be prepared for the big picture, but never, ever let it get in the way of making a single great film. Be a little more experimental and see what works as opposed to trying to force success. And mostly, remember that we as an industry exist to serve the audiences, to communicate with them – they have a voice in what we create as well. We are not here to dictate what they want to see, mostly because that’s simply not possible.”

Gunn does, of course, have a point that filmmakers and studios should remember to create movies that work on their own, rather than those that only work as part of a larger arc. However, it seems at least one studio learned that lesson the hard way, as Sony continues to rework its plan for Spider-Man. Whether other studios will learn from what went wrong with The Amazing Spider-Man 2, though, remains to be seen.

That being said, what Gunn fails to admit (at least within his short post) is that the movie industry is changing; shared universes aren’t simply a trend, but the way in which Hollywood is headed, for better or for worse. Though we still see plenty of standalone dramas and thrillers in theaters today, more and more action, sci-fi, adventure, and even horror franchises are building shared universes to varying degrees of success.

The reason studios are creating more shared universes is because audiences are interested in revisiting these worlds – building an ongoing brand loyalty. While viewers still want to see standalone movies, or movies that can work as standalone films, shared universes will likely continue to grow in popularity. What studios need to do, as Gunn suggests, is find the balance between creating single movies and fitting them into the bigger picture.

The Avengers: Age of Ultron releases in theaters on May 1, 2015, followed by Ant-Man on July 17, 2015, Captain America: Civil War on May 6, 2016, Doctor Strange on November 4, 2016, Guardians of the Galaxy 2 on May 5, 2017, Thor: Ragnarok on July 28, 2017, Black Panther on November 3, 2017, Avengers: Infinity War – Part 1 on May 4, 2018, Captain Marvel on July 6, 2018, Inhumans on November 2, 2018 and Avengers: Infinity War – Part 2 on May 3, 2019.