Superman is probably the most famous superhero of all time. Despite his popularity, however, his forays onto the silver screen have been decidedly anti-cinematic and often straight-up terrible. The question is, if the character is so popular and beloved, why don't Superman's movies work? The answer is more complicated than you might imagine, and only mostly Zack Snyder's fault.
Most people think it's because he has a bland personality, but there have been plenty of stories that have proven otherwise. His wealth of empathy, compassion, and kindness actually give him a unique perspective that is sorely lacking in today's age of gritty superheroes.
If that's the case, then, why are so many filmmakers struggling to capitalize on the Big Blue Boy Scout? It's worth noting that Richard Donner did a superb job adapting the character with Superman: The Movie - a film that wasn't afraid to be optimistic during the cynical 1970s. Granted, there have been some cool moments in modern Superman films, but it's all just so grim and depressing. If Hollywood has any hope of keeping the character alive for another generation, they need to tap into that optimism and exploit its sunny disposition. Otherwise, they'll continually be unable to translate the success of the comics to the screen.
Even if they do that, though, there are still plenty of reasons you can't make good Superman films.
He's Never In Real Danger
This may seem overtly obvious, but it's definitely been a huge problem for all of Superman's films. There have been varying degrees of power bestowed on The Last Son of Krypton for his on-screen portrayals, but most movies have shown him to be indestructible to the point where he can survive in space without the need for a suit.
Seriously, when your main character can't get physically hurt there are no stakes to get excited over. When the protagonist is always going to be fine, there's no drama to a story. We crave conflict and struggle in our storytelling, it's at the core of our desire for narrative. And it's really hard to get jazzed about a guy who's so tough that bullets bounce off of his eyeballs. Also, that was kind of gross, right?
It's Hard To Modernize His Story
Superman is built on old-school American values. His core principles have always famously been, "Truth, Justice, and the American Way." What does that even mean? The farther we move from the 20th century, the more those conservative mid-Western values seem out-dated.
The problem is that removing Superman from those values means losing the appeal of the character. Case in point: just look at how they tried to modernize Superman and his stance on killing in Man of Steel or Batman v Superman. Audiences were either upset at the betrayal of the character, or just apathetic towards his new, gritty persona. Basically, Superman needs to be wholesome to resonate with consumers, but consumers don't respond well to classically wholesome characters anymore.
He Has The Same Romance Over And Over
Every superhero has their true love. Spider-Man has Mary Jane, Batman has Selina Kyle (or Talia al Ghul, if you're nasty), and Superman has Lois Lane. The thing is, filmmakers realize that you can't tell the same stories over and over again... which is why we've seen many movies where Peter and Bruce romance other characters from the source material (or new ones fabricated whole cloth).
However, outside a brief flirtation with Lana Lang in Superman III, Superman seems locked into the same romance in every film. While he does have other romantic interests in the comics (the aforementioned Lana, or Wonder Woman, for example) Superman always comes back to Lois Lane, and their love story is often boring. It's been the same "normal woman loves impossibly powerful alien but they don't have many problems" tale for decades, and it doesn't translate well to film.
Kryptonite Is The Only Way To Create A Fair Fight. It's Also Boring
Perhaps the most massive problem that comes from Superman's overwhelming power is his inability to have a fair fight. Pretty much anyone who isn't a deity doesn't stand a chance against the Man of Steel. Thus, Kryptonite was invented. The irradiated chunks of his home planet are the only way to keep Superman in check (short of a red star). The problem is that it keeps showing up over and over again Superman stories.
It's become a crutch for lazy writers to humanize an inherently inhuman character. And here's the thing: when you take away Superman's powers, you're no longer telling a Superman story. Now you're just talking about some dude named Clark, and no one signed up for that when they went to go see a movie about a space god.