My wife and I watched Guardians of the Galaxy 3 recently (so good!!), and it got me thinking about James Gunn taking over DC movie universe. Actually, it got me thinking about why the “old” DCEU failed, and I think I can boil it down to a single thing: the writing.
I am a huge superhero fan. I grew up reading and collecting both Marvel and DC comics, but of the two I preferred DC, so I have read a LOT of DC comics over the years, and the thing where the DCEU failed hardest was the writing. The movies got a lot wrong, and also did some dumb things.

One of the bigger mistakes made in Man of Steel was the collateral damage created when Superman fought Zod. As this is Superman’s first *real* battle I would have forgiven a lot of that, had they followed it up properly. Had there been a scene, at any point after, where Superman made reference to the damage and expressed regret I would have accepted it. In Batman v Superman, if Superman had been the one to suggest luring Doomsday to an uninhabited area of town to minimize casualties and damage (instead of Batman), I would have nodded and smiled and thought, “Yeah! He learned something from his battle with Zod” and I think most of the audience would have accepted it!
One of the defining characteristics of both Superman and Batman is their unwillingness to take a life, and yet in Man of Steel we saw Superman take Zod’s life, and we saw Batman take many lives in Batman V Superman. When battling Batman in BvS if there had been a scene where (as an example) Superman mentions he could swat Batman like a fly but isn’t because he “won’t risk killing another person…..again” it would have been sloppy writing, but acceptable. Combine that with his reluctance to put civilians at risk or create unnecessary property damage and it would have shown Superman gaining experience as a hero and also shown character development. Plus, it would also show how clever Batman is by using Superman’s unwillingness to even risk taking a life to his advantage.
Batman’s change toward extreme violence could also have been justified had anyone take time to explain it. There is a quick scene in BvS where you see a graffitied Robin suit displayed in the Bat Cave. Based on that scene I wrote a blog post about a few years ago that connected the “Bale” Batman movies with the DCEU. My theory was that (Robin) John Blake took up the Robin persona to fight crime in place of Batman after the end of “The Dark Knight”, and it ended badly for him. Bruce got SUPER angry about that, re-assumed the role of Batman, and got WAY more violent. I think there could have been a scene where Alfred tried to call out Bruce on the violence, incorporating my theory, and (again) the audience would probably have accepted it.
Two of the biggest failures in writing for the DCEU was having Superman destroy indiscriminately and kill, and not having him express any remorse or show any character growth; and having a massive change in Batman’s character with no explanation.
One of the other big errors the writers made was asking the audience to accept things that were frankly, dumb. The 2 biggest leaps the audience just couldn’t buy (in my opinion) were two deaths: Superman in BvS and the Joker in Suicide Squad. These two are iconic and beloved characters. Asking the audience to believe either are dead is a BIG ask, that we may have accepted had they asked properly, but they didn’t and I did not for a second believe that either were dead for good after either scene. Had they been better written I may have been able to summon enough “suspension of dis-belief” to accept them, but….. No.
These are a couple of my issues, though there are far more. Despite the many problems, I do still love many of the DCEU movies, and enjoy them. The writers got quite a few things wrong, but they got quite a few things right too! (The above scene, for example.) I still get my enjoyment from them and re-watch them regularly, and I am very much looking forward to what James Gunn has planned for the new DCU!