This is wrong-headed but pervasive thinking. In reality, rich people are just people. Politicians are just people. Celebrities are just people. All people are corrupt to some degree, and some people are corrupt to a large degree.
It's easy for you to imagine a very wealthy person slipping into amoral hedonism, but I contend that their wealth has little to do with it. I once visited a rural Siberian village where a significant contingent of the older men wandered around town drunk. It was so commonplace that 10-year-olds in the community could tell you which of the men were angry drunks, and which ones could be led by the hand back to their homes. Those men lived on food rations from the government, and the first thing they would do when they got their ration of bread was to take it to the local convenience store and trade the bread for vodka. There are probably lots of reasons why someone would wallow in drunkenness for months at a time, but one reason is that they're just following whatever desires they have at any moment in time. Amoral hedonism isn't strictly a rich man's game.