These guys are basing their position on information that comes to them from what they consider to be informed, educated, reliable sources; remember that most doctors, even if wrong, honestly believe that steroids are dangerous to your health. The politicians mentioned above are not acting with malice. Everybody acts like these guys know the truth and choose to have these positions anyway.
Since the overwhelming majority of the medical community (again, even if wrong) will tell anyone who listens that steroids are horrible for you, how can you blame the congressmen and senators for believing them? If a large number of experts kept telling you something, would you take their word for it or would you go searching for someone to tell you different and then believe that person? Set your personal beliefs about the subject aside and think about it from their perspective.
The problem is the misinformation itself, not the people who rely on it in good faith and with no malice.
/karp