An Olympic season is one of maybe 3 or 4 that some of these athletes have available to them to make their mark. Taking even one of those away from them can irreparably set back their career.
http://www.drjohnm.org/2012/06/cw-its-settled-long-term-extr...
Also, I would prefer if we applied ethical considerations across the board.
We already see countries/coaches/teams pressing athletes to use performance enhancing drugs.
In the end, sports competition have exactly 0 purpose in this world except for entertainment and personal feeling superiority.
And to pretend that this is some vacuum that athletes are making this decision in is ridiculous. Allowing steroids in competition means that you have to use steroids to compete. Were you capable of making these types of decisions as a child? Do we allow children to harm themselves or do we condemn it? Should we allow adults to do this when there is a very clear external factor that motivates them?