I dislike performance-enhancing drugs (PEDs) for several reasons.
Some of them are rational, such as the fact that they create a vicious cycle of doping and introduce yet another hazardous element to a sport that's already antithetical to physical health.
Others are irrational.
In short, I dislike PEDs because they're a form of cheating that doesn't take skill or craft on the fighters' part. I respect the kind of cheater who gets away with it because of his own skill, like Floyd Mayweather sneaking in elbows where the ref can't see them.
PED users generally get away with it due to a lack of oversight, not any particular skill on their part.
But there is one thing I like about PEDs: they, along with excessive weight cutting, serve as an excellent example of the Prisoner's Dilemma.
If you haven't heard of it, Wikipedia's got a whole article on it (which, I learned, cites doping as an example. Kinda took the wind out of my sails, to be honest). If you'd rather not slog through it, though, here it is in short.
Two criminals are captured by law enforcement and placed in separate rooms. Neither has any contact with the other and they have no extensive prior affiliation other than the crime for which they were imprisoned. There isn't enough evidence to convict the two of them, so the officers come up with a solution. They present each one the following offer: they can either keep quiet or give up the other. This produces three possible outcomes.
1. One talks and the other doesn't. The former goes free and the latter goes to prison.
2. Both talk. Both go to prison.
3. Neither talks. Both go to prison on lesser sentences.
Now, the best solution overall is for neither of them to talk. The problem arises when you consider the ramifications of the choice.
If Prisoner A keeps quiet, he will either be on equal footing with Prisoner B or be much worse off. If he talks, he'll either be on equal footing or much better off.
In short, when dealing with someone you can't trust, it is better for you to give them up.
This thought experiment can be applied to many situations; a good one is nuclear proliferation. It would be best for the world if they were all gone. It would be the best for each country if everyone but them got rid of theirs. Nobody wants to be the sucker who actually complied with an order to destroy their arsenal, so the world gets into a progressively crappier situation.
The parallels with doping and weight cutting (which I do not consider equivalent, just both examples) are readily apparent.
A clean sport with fighters competing close to their walk-around weight would be wonderful. The fighters would have greater longevity due to the lesser strain on their bodies and the fights would likely be more entertaining, since they'd be closer to 100 percent on fight day. What ruins things is that nobody can be confident that their opponent will be clean and are afraid to be the only one without those advantages.
Fighters don't just dope to get better. They dope because they feel like everyone else already does. Until you can set up a system in which fighters can know with 100-percent certainty what their opponent is on, they will keep using banned substances.
It's only fair.