Caffeine helps keep long-distance truckers awake, but it's an addictive drug with serious side-effects. Would we ban professional truckers from drinking coffee?
I think one of the problems here is that, thanks to the Olympics, the public has a skewed way of looking at sports health. The Olympics is a competition for amateur athletes, people who have Day Jobs. It's supposed to be a test of the natural abilities of people who don't do sports for a living. In any test of natural abilities, drugs have no place.
But NFL football, MLB Baseball, NBA basketball, NHL hockey, etc, are not tests of the natural abilities of amateur athletes. They are commercial enterprises aimed at giving the fans the best show, the strongest professional athletes turning in their best possible performances. I see no reason for performance-enhancing drugs to not be allowed in this arena.
I don't even think I would have a problem with genetically altered athletes competing professionally. This is about entertaining the fans, not about keeping something pure and wholesome.