Though how do you police drug taking in a category where taking testosterone is the norm?
Just as with any sports category, why should taking testosterone be allowed at all?
You choose to dope, you take the consequences.
I once worked for a rail company. All office staff, including temps, had to sign the same alcohol and drugs contract that the drivers signed. In any other office job, it would be nobody's business if you came into work with a hangover, as long as you got the work done and behaved appropriately. It's not even uncommon for that to happen. But at this rail company it would be a serious disciplinary issue, potentially instant dismissal.
In order to work there I had to accept the consequences of doing a completely legal and normal activity.
If you want to compete in sport, you have to accept certain restrictions on your life. Restrictions that are there to protect participants. You chose to take banned drugs, you have to accept the consequences. You chose to take banned drugs, you exclude yourself from the sport.