The Lord of the Rings, Avengers Universe, 1984, etc. just pick your favorite genre comparison, of dark, dirty graphic novels.
No one is completely evil or good
Everyone has reasons for being the monster, good person, or something in between, always haunted by past traumas. Much of the complex, brilliant plot is directly connected to the protagonists´ backstories, which makes it even more compelling, because the reader is expecting and getting what she/he is waiting for. Especially the evolution from weak to superhuman, more and less powerful, and the thereby modified morality, ambitions, and personal goals of the characters are used to demonstrate the inner fragmentation of human psyches, no matter how demolished and totally wasted they already were before.
This white and grey morality with all its cognitive biases, filter bubbles, ivory towers, and even stranger metaphors still to be developed (in the age of cyberpsychology and coming VR and mind upload psychology and the even more interesting psychopathology and psychiatry) is maybe the driving force of this thing. Not the violence, action, complex plots, but the underlying question of what makes one humans´ hell cellar anothers´ heaven and how everyone can justify even the worst actions with ideology or personal identification and emotional connection to the coffee mug, lucky charm, or weapon of mass destruction.
It´s much more easygoing and mentally comfortable to stay with black and white morality although this can easily escalate to black and white insanity, but most people don´t even notice that jump on the madness scale because they´re already in the zone.
Maybe one has to be a bit crazy to create something like that.
The result is not just a bit controversial, it´s closer to the crazy artist stereotype than most in the already wacky creative business.
I don´t really want to discriminate average normies, boring and coward opportunists, here, but the statistical distribution of madness and substance abuse in arts tends to, ahem, slightly tend towards authors. Maybe because living in ones´ head is like a permanent finger on the red bonkers button, while extroverted people getting their kick from others are more endangered by being made crazy by their fellow naked apes or, strangely, their absence in the case of isolation. Which kind of closes the circle back to the wacky creative business again. „But I am really normal and mentally healthy!“ Of course I am.
Might be over my head
Especially because it´s often described as a kind of meta hommage to graphic novels and comics in general, there are certainly tons of elements I can´t get with my poor, current knowledge, because I have to grow my beard regarding these genres. Things that seem to be often mentioned in context with this work are praising the genre, genre deconstruction, deep and complex milestone of the genre, the mentioned morality compass, so I´ll just steal these words and run with them fast. Instead of thinking too much about the hidden depths as an unworthy, bloody rookie in the more colorful, or in this case especially crimson and black, visual reading department.
Incredible superiority and suffering
The überhuman Dr Manhatten part is in strong contrast to the gritty, somewhat apocalyptic, setting on a bleak and dying earth. Interpreting the meaning and deeper sense of this plotline could mean great extra fun. Again, the ethical question of personal decisions kicks in, because he obviously could have fixed close to any problem with his superhuman powers, just as other characters could have been a bit less violent. Although that might have made the whole thing a bit boring.
Less bigotry with snobbery as an icing on the elitist cake, please.
The irony of the fact is that this is one of the only graphic novels that got honored by both Time magazine and the Science Fiction and Fantasy hall of fame.
It may incredibly still take even more time until comics and graphic novels are seen as as important and worthy as normal literature, something so ridiculously showing the snobbery and elitism of the established literary business that it really hurts. But the more incredible works like this one are produced, the more the conservative, intolerant hater trolls (how ironic, because they´re mostly offline in meatspace because social media is another evil, new, direct democratic pull media thing they can´t control with their push media manufacturing consent propaganda) have to change their unsubstantiated, bigoted opinions. As if the comics code (Heck, they even made their strange propaganda approval quality logo) with its fascistic, sexist, homophobic, racist, etc. quite a long list, censor tendencies wasn´t already ridiculous enough until it silently left the stage after having luckily been made meaningless. If anyone would have done this with „real books“ or newspapers, it would have been called cooptation, dictatorship, or mind control. No wait, the last one is of course just a leftist conspiracy theory, as if anyone would do that in democratic countries, your decisions and ideologies forming your personality are totally not manipulated!
That´s how it used to be, not how it´s fictionally described
We see no dystopic future or a cyberpunk nightmare, but the exaggerated description of the darkest sides of our current system. Go to a slum or even into a developing country and discover the worlds of murder, torture, and sexual violence, just without superpowers, and here comes the savior stuff of course. And to overstrain the morality question, it´s of course always very important who is good or evil, attacker or defender, freedom fighter or terrorist, prophet or devil, in each decent, short, and easy, optional religious, war.
Long time impact and the beginning of a legacy
Take The Boys, adult animation, extreme horror, all the magnificent shock effects that go deeper than just under the skin, but vivisect society with its flaws, grievances, and thereby inherent madness itself. All heirs of turning the Disneyesque unicorn rainbow pony farm thing upside down, letting it degenerate, or, depending on the personal standpoint, evolve to postmodern, big history deconstructions of what was never good and harmonious, but just painted that way. Which is even sicker than the worst war crime genocide human experimentation/ extermination/internment/ concentration/ add favorite downplaying euphemism, cucumber here, because it´s the polarized, suppression fueled mindset of cultures that makes such atrocities possible. Not just great entertainment, but enlightenment and epiphany come with the watchmen too.