The problem with allowing them to use is they will use more and more.
How do I know because I was once one of them in an unregulated activity where using was/is permissible. Back when I started in the early 80's it was somewhat mild, but by the time I stopped using in 96 the dosing was at minimum 10 times the amount that I was using in 83. By 1990 even the local competitors were now using GH and insulin because they pros were already using this, but the bad thing at the local level we had no clue as to what we were doing with GH and insulin. It was and has always been a big lab experiment for bodybuilders who have no concern about testing. So the dosages continued to increase.
When it is unregulated "some" of those users are going to die, go to jail, kill loved ones (Bertil Fox, Craig Titus, and Chris Benoit to name a few), destroy relationships or personal health. It is unpredictible which side effects will hit each user. Some might not show any at all, but for the most part many will experience at least one or more of the temporary side effects. The ones that hit me were extreme mood swings that were at times very violent so I can relate what happened here in Atlanta with Chris Benoit though luckily I never quite crossed a line of finality that he did and the majority of what I did was punching holes in things that I would have to repair later. Throuh the years I have seen a variety of other side effects with friends and associates ranging from gyno in men to the permanent masculine looking faces and deep voices in the women. I heard this past week that one of my sources and a guy that I trained with on occasion has died due to health issues that may have stemmed from his heavy usage.
In my opinion if legimate tests were done at random through the years it "may" at least scare some of the competitors to "hopefully" keep the dosages lower. Notice I did not say it would end usage, but when it is unregulated things will get much further out of hand. Some might say let them use, but regulate the dosages. It won't work and who is going to regulate the dosage. Now testing has no basis because a competitor could just claim it effected him/her differently then the other field of competitors.
I could go on with my point of view and opinion, but maybe this will shed some insight to the original question. By the way I have no solution to stop usage because you have to impact the mentality of those involved and those around the athlete supporting the use.
I haven't posted in a while, but the Chris Benoit ordeal hits close to home since I am in the Atlanta area and personally know some of these guys. I have watched the personal self-destruction and it is hard to watch people you know do this to themselves. Now that I aired this out it is back to lurking mode for me.