What's so Good with Doping?

One thing I never seen written down is why doping is so bad. Everyone knows it is bad, but why?

Surely it isn't just because it is "cheating". If everyone was allowed to use any substances they wanted, no one would cheat, and we would get excellent results in the sports.

However, the athletes do not want doping allowed - not the clever ones anyhow. If they were allowed to use any substance, they would end up with doses that far exceed what is good for them long term. The result would be short lived athletes who win for a short time and then die fairly soon from the drugs they have taken.

In 1904 a marathon runner collapsed after the event, and had he taken more drugs than he had, he might not have recovered at all. There have since surely been many other cases like that.

The cynicism of it is that no smart athlete wants doping to be allowed in general, but any athlete can be tempted to take drugs himself.