From TFA:

    Many frauds start out as a legitimate business or idea that simply gets taken too far through some combination of greed, loose morals, and overconfidence. Once the ball gets rolling, money begins pouring in, and a certain amount of power is obtained it becomes difficult to stop the train.

    People will do just about anything they can to ensure the money and power continue indefinitely.

This is at the root of many frauds I've seen in recent decades. In other words, most of these frauds are actually Crimes of Opportunity.

https://en.wikipedia.org/wiki/Crime_of_opportunity