It can be true, but I'm not fully agree with that. In the past money perhaps isn't the major thing for scientist's life, but the world now says different thing. Many of them are concerned on how to make good money even some of them are truly dedicate their life for knowledge. So, it depends on their own motivation.
not unmotivated with money, we all know that money is a basic need of every human being, but human beings have a deprived nature and therefore they are always looking for more.