My personal opinion and reaction to the Synder-verse Superman having a movie version that's R-rated, even as an alternate cut...
... I HATE the idea.
Superman is the greatest hero in the world. Batman may be cooler and Spider-man may be more complex, but Superman is the ideal. Superman is the standard. He's the bastion of morality, virtue, and kindness balanced with power and strength. He is the living embodiment of truth, justice, and the American way. He's the hero little children grow up pretending to be as they pretend to fly through their room with bedsheets wrapped around their neck. He's the hero other superheroes wish they were and aspire to be. He's the superhero even Batman says is a better man than he is.
Superman is hope. Superman is joy. Superman is the purest, most iconic superhero in the world.
And there's a reason dozens of Superman-knockoffs have come and gone without resonating nearly as well. Heroes with his powers but lacking his code of ethics. Murderous, violent, angry superheroes with capes like Supreme, Prime, Sentry, Apollo, Hyperion, etc... You take away the "light" that Superman brings to his world, you take away his inner gentleness, his kindness, his humble heart and modest nature, and you strip it away to leave only the dark, brooding, angsty, violent shell behind and you have a character that is no different than his countless, less-successful rip-offs.
It has been over 30 years since I've seen a Superman that inspires humanity and rises above the threshold of human pettiness and weakness. It's been SO long since I've walked out of a Superman film in theaters with a hero that can be a role model to children the same way he was role model to me as a child. It's been so long since I've see the greatest hero ever INSPIRE me and a new generation of future comic fans and superhero-lovers.
R-rated Superman is... is wrong to me. It misses the point. It misses the point so far it's shot into space and orbiting Krypton.
If there is one hero, ONE hero, that should be the hero that stands as a symbol of something BETTER than the mindless violence and murder of mainstream comics, it's Clark Kent.
Superman is for kids, and I refuse to say that that's a bad thing. The reason he has endured so long and resonated so strongly is because he appeals to the kids and the kids at heart.
A hero is more than his powers, more than his costume, more than his strength and the amount of flashy destruction and cool battles he can have.
I haven't seen this hero done justice in decades...
And, I won't lie, that seriously bums me out.