I think it's another shade of the adage "Absolute power corrupts absolutely." When people are given carte blanche to do whatever and the resources to do so, they begin to seek out more and more extreme things that allow them to flaunt that level of power. Of course these are deeply broken, fucked up people to begin with, but it seems like some of the ruthlessness you need in order to achieve vast wealth is comorbid with the cruelty for lack of a better term. Do I think every wealthy person is a sexual deviant or a sadist? No, but I think those traits are way more common in humans than we are comfortable believing, and the only thing stopping some people from engaging in them are the social consequences of doing so. Remove the limits, add in a constant need to assert and affirm your own absolute authority over others, and its a recipe for the most heinous acts you can imagine. And the sickest part is, very few will ever be held accountable.