Let’s consider how we meet The Joker in that opening scene which will go down as one of the greatest heist scenes ever shot. Joker stages an elaborate plot to rob a bank and even though there’s a dramatic reveal near the end we all knew it was him because the clip had been released as a promo long before it came out. So everyone who saw that film was already in the mindset, “Here’s The Joker, what crime is he going to pull?”

The thing is, he doesn’t pull a crime. He stages an elaborate bout of vigilante justice worthy of Batman himself. The bank is a mob bank. It houses millions of dollars of funds gained through extortion, drugs, theft, murder, you name it. Not only does The Joker rob the bank, he does so in a way in which all his criminal accomplices murder each other one by one thinking that they’ll get a bigger cut if they do. This is supposed to look diabolical bit of insanity but it’s really him immediately eliminating five dangerous murderers while he’s literally in the middle of crippling the mob financially.

Swap The Joker out for, say, The Punisher for that scene. Sure, he’d be a killer with a gun and killers with guns are how we know guys are bad in Batman movies, but the real result is that The Joker completes a major anti-mob strike while getting a quintet of thugs off the streets for good. He doesn’t kill any civilians, and only wounds the manager with a shotgun in self-defense. Even then he lets the guy live with a joke.

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Now granted, The Joker also wages a war against the institutions of law in Gotham including assassinating judges and commissioners. That is clearly wrong, but again, look at it from The Joker’s point of view. We know that the police and the courts are corrupt. It’s one of the main reasons that Bruce Wayne became Batman in the first place and why he only trusts James Gordon and Harvey Dent. No one else is incorruptible.

And if the system is so broken that it requires a man like Batman to dispense justice then why is it worth preserving in the first place? If you’re The Joker and you hate the mob then why would your plans stop at robbing them and killing their henchmen? The upper echelons all have the supposed legitimate government catering to them, which is the sort of joke that might indeed make a man become The Joker..