The economics of pumpkin bombs
In the world of comic books any individual who has more than 5 million dollars in saving or assets immediately becomes bat-shit insane. It’s a strange rule, but it seems that every independently wealthy individual in superhero comics decides that fighting/committing crime is the best way to spend their free time. They ignore possible hobbies like golfing, yachting, and collecting antique cars and go straight into wearing a mask and creating a global organization designed to save/destroy/conquer the world. The examples in comic book fiction are nearly limitless.
Of course, the author ignores the problem of sampling error: millionaires in comic books cannot be considered a representative sample of millionaires in the alternative worlds they inhabit. But still, he has a point.