I had written a long post that was massive even by my verbose standards, that explained why people enjoy grimdark and a character study of superman and why grim doesn't work with it but I'll cut it down.
People think dark=mature, immature people write stories in this vein resulting in immature dark stories.
The more optimistic and happy a work is, the more people want to darken it to justify them liking something so "immature" (See My little pony fanfics... or don't and not take a hit to SAN)
DC's live movies are getting it's ass kicked by it's marvel counterpart. Dark knight closed the huge gap so they tried it's dark formula with the next movie, Superman. This tone works with Batman because he is the dark that shuns the light, does what he needs to win, even if it isn't nice, because his foes aren't nicer, but not for his foil, Superman, the nice guy, the god on earth who brings himself down to our level because he wants to bring us to his.
I don't mind the fact that one's CHARACTER makes one more RELATABLE, but a good STORY can make a character more SYMPATHETIC. And I've always thought that supe's story is one of trying to be good so you can be an example of greatness in all trials. Its almost a religious allegory(regardless of your opinion of faith) rather more subtly done that the blatant Jesus imagery in MoS.
The appeal of a grimdark superman rather ironically speaks to one of the themes of superman itself:The tall poppy syndrome, rather more than the mega rich Batman who spends money on toys for himself How dare one man have all that power, and how dare he not abuse it to all hell like I would. He can't be good all the time and he must be secretly evil, his optimism a facade See my line about optimistic works above.
That said, I can see how a dark superman CAN work, I just don't think Man Of Steel did it well or did it to it's fullest. A dark superman would focus on his story of learning morality. Have him wonder WHY he can't just break loose and abuse his powers, have him doubt if he can save everyone all of the time, whether he would have the energy to and whether he would want to, with all the ingratitude he gets and all the evil he sees all the time.
But he knows that if it does, it would feel wrong because he had been taught that it is wrong, and through his growth he would be guided by his moral adopted family who will show him why he feels it feels wrong and why it is, even if they don't have all of the answers, they will try to teach him goodness rather than "Let the kids on the bus die" and "let me stupidly sacrifice myself even though you could do it without loss". A God on earth being cared for and under the power of two old but caring humans. It still keeps the Concept of superman, A powerful being trying to be good, but a dark superman story would focus on his doubts and whether it is all worth it.
And if you want to do a grimdark superman movie, honestly, I say adapt Irredeemable to the big screen. Because I'm sure that if Hollywood tries to make another darker superman movie, it'll end up like the story mode of Injustice... with more batman.
God, I cut it down and its still massive....
and zod was awesome.
