The NCAA has long declared that its participants should remain amateur athletes. This is also the case with Olympic athletes, but there is a key distinction in the way that the two entities define amateurism. While neither is allowed to receive payment for their services, Olympic athletes are allowed to earn endorsements for their likeness.
The NCAA has formed a working group to consider how it can modify its rules to compensate athletes, and one of the possibilities is to allow them to profit from the use of their likeness.
The evolution of how current NCAA athletes are compensated has been underway for over a century.