Kind of springing off of my 'DC doesn't want 'weird' Superman stuff" thread, there's the idea of "why doesn't DC just go back to X take on Superman that everyone loves and would so obviously work?" And having thought a little about that, and what WB seems to want, I've come to the conclusion that, at least in broad strokes, there's literally no 'traditional' version of Superman that would be approved of as a headliner. Bits and pieces of them thrown in the mix, sure, but not the whole thing.
First, let's consider what WB actually wants. The thing is, I don't think it's to make things dark and realistic and dour. Man of Steel was the alleged poster child for that, but it spent a good chunk of the runtime having Jor-El lecture on how uplifting and inspiring Superman is and how he's gonna take us into the sun and it stands for hope and everything's gonna be okay now. Jor-El having previously ridden a dragon straight out of LOTR at the beginning (including a visual shout-out to a Silver Age Superman story with the shattered moon) before doing some space kung-fu. Heck, for all the talk of the people at the top hating Superman, by all appearances they're showing Batman as the bad guy in BvS to build up Superman, a movie that will also confirm the canonical existence of Robin and Aquaman.
So what's it want? Dramatic. Epic. Weighty. It doesn't filter everything down to borderline-gray because that's cool - Dark Knight had plenty of color in it - but because in this Very Serious Story having the red and blue and yellow overpower everything would be a distraction. Same with him smiling, or wearing his underwear on the outside, all of which would be cracks at the foundation of the take on hi they want to build. Really, this isn't a process that began with MOS. Superman Returns showed him as a figure of nostalgia and depressed God separated from the woman he loves who lays down his life for us (because what could be weighter than Jesus?), and began the process of toning down the costume. Hell, go back to Chris Reeve, you've got almost an hour of frontloading Krypton drama and farm soul-searching and Fortress declarations of purpose before it's considered safe to put Gene Hackman on the screen. They go back to the genius enemy of Superman's philosophy (Man versus God! David versus Goliath, Intellect against Power, Altruism against Hate!), the alien from his home planet (An even match! The lure of his homeworld! Familial drama!) and the other alien from his home planet with bone spikes (The Death of Superman! Laying down his life for the greater good! Rising to save us again!), rather than Metallo (a robot...with Kryptonite stuck him him? Sure.), Parasite (he...eats stuff, I guess?), Bizarro (they'll laugh us out of the theaters!), Brainiac ('Brainiac'? With bottle cities? Really, man?) or Mxyzptlk (you're fired, get out). Hence also Clark being focused on less and less, because he's not the epic part. They know what they want, but they haven't gotten to a point where it works yet, because unless they get someone brilliant on the project it never will. So why not an established, successful take? Well...
Champion of the People: This would seem to be a sure thing. He's tough, he don't take gruff, he's willing to show his stuff. Plus, down to Earth. Except the core of the thing is him standing up against the powers-that-be, and while they're willing to very slightly paddle in those waters in the comics, it's not shocking WB wouldn't do a movie about the biggest corporate icon on Earth fighting corrupt businessmen and the forces of industry for 2 hours.
Cosmic Super-God: The dude that fights weird stuff and goes on crazy adventures. But - again, as I went into in that other thread - what could less serious on the face of it and retro and undermining of everything they've been trying to do then that?
Drama/Romance Lead: Between Lois & Clark, Smallville and years of the Superman books as a soap opera, it's impossible to argue that Superman as romantic lead isn't a pretty major established way of handling him and his world, and one that's well-known and often well-received. But that's something more suited to long-form storytelling, unless they were willing to double down on those elements for the movie in a virtually unprecedented manner. Plus, between presenting Superman as an object of desire and often focusing much more on Lois, it's an approach that favors the women in the audience more than is typical with the character, and it doesn't take x-ray vision to see what your WB's and Disney's think of how much they need to care about that demographic.
Regular Ol' Superhero: The dude who goes to work with Lois and Jimmy and Perry, leaps out to change to Superman to stop Metallo or Prankster, maybe palls around with Krypto sometimes. The animated series take that Marvel Studios would probably do well with. But if you're WB, what's the in? He's just a generic super-dude. To make him work like that takes some serious nuance of character, and baby, WB don't got time for that, we got us some $$$ to make.
So there you go. Obviously they're less strict with the TV shows and the comics (though it's certainly still there), but the movies are big enough they're going to take control. And what's left when you take away the broad strokes of those approaches? Well, you've got a strange man in a strange land who's really hopeful, who'd lay down his life for humanity and is an icon and can hit stuff real good. You've got a guy without nuance who nevertheless lends himself to Hollywood-model capital-d Drama to go with the action. You get space-Jesus, a story that's worked out to some degree of success in Western civilization, you may have heard. And since there isn't an 'acceptable' other option, WB will keep hammering on that round peg until the square hole cracks, one way or another.