Machiavelli wrote it in 1513: men keep their word while it costs them nothing, and break it the second it does.
Five hundred years later, a man in clown paint says the same thing about morals and codes — dropped at the first sign of trouble.
Same diagnosis. Both watched people under pressure and saw exactly what happens.
Then they split.
Machiavelli's answer was to build carefully. If virtue can't be relied on, design the structure so it holds anyway — checks, institutions, systems that survive the people staffing them. Architecture.
The Joker's answer was that the whole thing is theatre, so tear the curtain down. Arson.
The diagnosis was never the point. Anyone can notice that people are weak — it costs nothing, and it arrives feeling like insight.
What you do the morning after you notice is the whole of it. Cynicism is a starting line, not a destination.