I personally would not agree with this statement. There are many factors other than money that motivate employees. There are even those (like Herzberg, in his famous motivation-hygiene theory) who would argue that money tends to be more of a cause of dissatisfaction than of motivation.
I would argue that money is more of an external motivator. A person who is motivated by money will be motivated to seek more money, not to do their job as well as possible. This is not what you really want in your employees. Instead, I would argue that the better motivators in the workplace are the motivators that come from within. For example, Herzberg says that employees are motivated by the chance to achieve things and to be recognized for their achievements. They want to do work that is satisfying and they want to have responsibility. All of these things are more important motivators than money. These kinds of motivators make workers want to do well at their jobs and to work hard rather than inspiring them to simply want to get as much money as possible (possibly without having to work hard to get it).