I read an interesting perspective on that a while ago.
The original idea of the Olympics (well, not original original, but original regarding the late 19th century revival) was that the Olympics were for amateurs only. If you made money from your sport, you could not compete in the olympics. You'd think that would lead to an equal playing field. It very much does not.
As a first effect, it limits competition to those with the means to train in their spare time, which means the upper class. As a second effect, it expands the circle to those who can pretend not to get paid for being athletes, which basically means those who can do sports while pretending to be in higher education or the military. One of the reasons the East Bloc did so well in the Olympics back in the day was that they saw it as a PR strategy, and thus got a bunch of people who were supposed to be soldiers but in reality were just training to compete professionally. Well, that and the 'roids. So by lifting the ban on professionals, the competition was actually opened up to people from far more backgrounds, because now the best athletes could actually make a living from their athletics.