If I ask the question why a person is never rich, it is not because he is lazy or unintelligent. He is not really rich because what he thinks he is rich does not really exist around him. When most people say we want to be rich, they do not mean just money. They mean reaching a place where everything is complete, including happiness, freedom, and security. Therefore, no matter how much money we accumulate, we will never feel rich. Because we are looking for something that money cannot buy.
Monetary wealth is only one aspect of life of course, but there are people who are poor and unhappy too, right? Money might not be everything, but not having any isn't good either.