All-Star Batman and Robin The Boy Wonder/WMG

Crazy Steve will be the villain to some version of Batman.
Why? Because it would be halfway decent use of such an awful work!
 * Brave and the Bold Batman would be a good good batman.

Crazy Steve is Mad Stan's dad.
What? You know it makes sense!

Frank Miller has lost his feeble mind.
Self explanatory.
 * To be fair, this is supposed to be Wild Mass Guessing. That's just obvious.

Frank Miller is writing one Stealth Parody after the other.
He was so disgusted by the Dark Age turning into a Dork Age that, somewhere along the line, probably when he was writing the Dark Knight Strikes Again, he decided to relentlessly parody the worst aspects of modern comics, while never letting on that he's writing parodies just to see how seriously people take it.

Alternatively, he was so disgusted by the Dork Age that he decided to always take large amounts of drugs before sitting down to write comic books.

Eventually all comics will be like All-Star Batman and Robin and The Dark Knight Strikes Again.
Okay lets see if I can explain this, When Frank Miller wrote The Dark Knight Returns comics were in the Bronze Age, they were realistic and sometimes dark, but there was still parts that were light hearted and silly (Wolverine teaming up with a leprecon anyone) so Frank Miller decided to do something different and take the dark realistic parts and turn them up to eleven, that gave us TDKR, unfortunately that was released around the same time as comic books that were equally dark and edgy, Watchmen, The Killing Joke, Batman: Year One, etc, and so people started copying them until we got to the Dark Age of Comics where that point of extreme has become the normal tone for almost all comics, then Frank Miller got hired to kick off All-Star Dc Comics, which was suppose to be basically DC's answer to Ultimate Marvel, so Frank Miller did what he did with Batman: Year One, he took the dark and edginess of modern comics and turned it up to eleven, which brought the dark and realistic feel all the way around back to silly and absurd, the result was The Dark Knight Strikes Again, and All-Star Batman and Robin. So if comics keep trying to get darker and edgier than Eventually comics will be like All-Star Batman and Robin, and The Dark Knight Strikes Again.
 * Grant Morrison was hired to do All Star Superman first and you don't get less ASSBAR than that.
 * Maybe most Superhero comics but not every creator in the medium cares about what Marvel and DC are doing.

Superman has No Fourth Wall.
He knows exactly the kind of work he's in and refuses to demean himself by taking it seriously. Instead he just does things like grab a car and walk it across the ocean just for the hell of it.

Batman is syphilitic.
According to Word of God, ASBAR is part of the same continuity as Year One and The Dark Knight Returns. Year One was, at the time it was published and until somewhat recently, batman's canonical origin. So somewhere along the timeline, the Dark Knight Universe split off from the normal Universe. Between Year One and All Star Batman and Robin, clearly, Batman hooked up with Catwoman and caught something.
 * Didn't he say himself that their first time happened down in the sewers?

Batman and the Joker are Out of Character because they've switched personalities.
This would explain SO much.

Frank Miller is trying to make a Shout-Out to the Golden Age, but has failed miserably.
This primordial, psychotic version of Batman seems to hearken back to the days when he actually killed people (and showed little remorse for doing so), and the grim, scowling Joker is just how Miller chooses to reference the character's original debut, in which he had absolutely no sense of humor whatsoever. It's heavy-handed, true, and it may just seem to be a decidedly lame re-hash of Sin City, but this can be chalked down to Miller's long, slow decay as a talented writer.

Frank Miller is intentionally trying to make it So Bad It's Good.
Frank did say it wasn't a parody.Plus its a Fountain of Memes for the goddamn Batman.Frank was aware he'd suffered a Creator Breakdown,so he decided to do the best he could:create a Narm filled comic that we can't help but laugh at how stupid it is.

The Joker wrote All-Star Batman and Robin.
Somehow,the Joker burst out of the comics and slit Frank's throat.He's been masquerading as Frank for years,and wrote All-Star Batman and Robin For the Evulz.

This was actually a really great story in Frank Miller's head.
It's actually a really awesome story in the vein of Batman: Year One, but unfortunately Frank Miller is under a devestating curse that causes him to write words that have nothing to do with the story in his head. The curse makes it so that the story is still coherent enough for poor unfortunate artists to work with but is actually really really awful, and he doesn't even notice because the same curse causes him to reread his work as what he meant to write. A similar system is in place for when he draws his own work, as in The Dark Knight Strikes Again. Jeph Loeb is under the same curse. How and why? Because Dan Didio has in it for the character of Jimmy Gordon Jr. and made a deal with the devil to make sure that Loeb and Miller couldn't continue to develop the relationship (both of them focused on the relationship between Jim and his infant son).

Which means that Christopher Nolan had better watch his back ...

All Star Batman is the Start of Darkness for DKSA's Dick Grayson.
Word of God is these are the same characters that later appear in The Dark Knight Returns and The Dark Knight Strikes Again. In those stories, Dick Grayson was. It's never explained how this could have happened to one of DC's oldest and most successful heroes. On the other hand, this is a Dick Grayson who was abducted from the site of his parents' murder by a psychotic cop murderer who was already stalking him even before he was orphaned, and who locks him a cave and forces him to eat rats to survive. Any child with trauma like that isn't going to grow up to be Nightwing.

Batman Was Abused By His Mom
Bear in mind, most of my knowledge of ASBAR comes from Linkara's eloquent dissertations on the subject; but when the line "I touched my mother's breast. It bled on me." came up, and Linkara pointed out the incestuous implications of the wording, it occurred to me: this explains everything.

This universe's Martha Wayne sexually abused her son, causing severe psychological damage and impaired/skewed concepts regarding love, sex, and appropriate/inappropriate behavior that ultimately resulted in him kidnapping and terrorizing a vulnerable, underage boy and initially trying to force him to live off of rats in a cave, against his will, for no other given reason than "Because I did it." Bruce is genuinely messed up.

Crazy Steve is actually...

 * A time traveling Jason Todd in one of his crazier depictions. It's all part of his plan to discredit Batman and screw with Dick's mind
 * A depowered Superboy Prime: Certainly crazy enough.
 * A clone: All a plot by Lex Luthor to replace all the superheroes with idiotic caricatures. He also switched Superman, Wonderwoman, and Green Lantern.

Dick Grayson's parents were murdered by the Goddamn Batman
The first issue makes it clear Bruce Wayne was already watching Dick and considering him for sidekick material. Back then, though, Dick Grayson wasn't sidekick material - he wasn't an orphan. If Batman didn't know Dick Grayson was going to lose his family, this would have been incredibly premature. The only way Batman planning to recruit Dick makes sense is if he was willing to assure the 12-year-old became an orphan. At best, Wayne knew Graysons were going to be shot and did nothing to prevent it. At worst, he hired the hit-man himself.
 * This version of Batman is established early on as a killer, crashing through police cars without any thought to assuring the survival of the drivers. He also views what he's doing as a war - and in a war, innocent casualties are inevitable.
 * To be fair, these cops kinda deserved it.

Crazy Steve is Chester A. Bum
After seeing the Dark Knight Chester was awestruck and felt a newfound obligation towards his social responsibilities. Unfortunately, after years of drug abuse he had no concept of how to apply his new found philosophy other than direct imitation. Contacting the Future Nostalgia Critic, he travelled into the Millerverse and bulked up by stealing a massive batch of venom from Bane and offered his help to Batman, but upon being declined, he beat him to a pulp and usurped the mantle of the Dark Knight. The Joker in ASBAR is in fact Batman in disguise, which explains why we have a poorly shaven, manic Batman who talks in slang and a brooding, humourless Joker (all his crimes in the series are simply faked to lure Chester into a trap). Chester/Steve will finally realise what a horrible person he's become and attempt to commit suicide using Joker toxin. Unfortunately this doesn't go as planned and instead it pastes a permanent evil grin on his face, shatters his already marginal sanity and turns him into Ask That Guy with The Glasses. At some point in-between The Dark Knight Returns and The Dark Knight Strikes again he once again usurps Batman, accounting for both the sudden creepy undertones with Carry Kelly as well as why the Batman we see in Year one and TDKR are consistent with each other but don't match the one we see in ASBAR and TDKSA.
 * Oh my God, this is the greatest WMG I've ever seen in my life!

Frank Millar is trolling the fans.
Contrary to supposedly going insane, Frank is still capable of writing great Batman stories. Why doesn't he? Because he's a troll! At some point, he discovered the Internet(and 4chan), and decided to mess with people For the Lulz. The whole series is made purposefully to evoke So Bad It's Good Narm Charm and memes. Why? Because Frank's the Goddammned Millar Man, that's why! One day, he will have a crossover with Snowflame who knows no pain, in order to deal with the ultimate evil: a deadly bee weapon! Bees, my God...

The Reason for the delays is that Jim Lee keeps trying to get away
Reading the exploits of Crazy Steve is taxing enough for any sane human being. Just imagine what it must be like for poor Jim Lee having to not only bring Frank's luancy into glorious, twisted two dimensional life but also put up with his horrific author's notes as well. Jim tried to escape several times during the comic production but was promptly recaptured by DC and forced to continue illustrating. He finally managed to escape to a small shack in Antartica where he sleeps on a bed of dried Elephant Seal feces and lives on a diet of nothing but snow, moss, fish heads and Penguin colons. And he still preffers it to Frank. Unable to find him, DC was forced to cancel the series and have delayed Dark Knight: Boy Wonder until they track Jim down. Pray the never do.