This is why steroids are banned from athletic competition, for the safety of the athletes. Creatine is legal, but so were steroids at one time. Creatine gives an athlete an edge over another athlete not using creatine for a simple reason. Creatine allows the body to replenish ATP sources quicker, thus allowing a person to exercise longer without fatigue and to recover faster. Creatine allows you to do more intense workouts in shorter time for this very reason.
Creatine is legal because there has been no serious short term or long term side effects known.
This is because creatine is relatively new and not enough time has past to determine long term effects. We feel that until the long-term effects of creatine are discovered, we support having creatine on the banned list. This is done for the well being of the athletes.