For all the righteous indignation we display after the fact, professional sport is a spectacle; an entertainment. We watch it because we enjoy that spectacle and get off on the competitive element. Most of us have no hope or desire of emulating the participants. If one of our heroes 'cheats' (or at least does so better than his rivals), it might spoil the thing temporarily if we like to believe in the Corinthian principles, but who's deceiving whom? Self-deception (or suspension of disbelief) is at the core of all sports supporters; the idea that any of it is uninfluenced by greed, mendacity, the sheer need to be better at any cost, is laughable. Lance is a particularly dislikable example of the breed, but he was also bloody successful and great to watch. I don't like having my nose rubbed in the fact that I liked to watch cheats cheating, but that's what it adds up to. It's up to sports authorities to do their best to enforce their rules, but if the spectacle's good (and I can be arsed), I'll watch it anyway.
Remember, even the (few?) guys who don't break the rules are doping. Anything that improves performance through supplementation or pain relief is doping, to all intents and purposes. It's the scale, the effect and the cost that varies. I limit myself to beer and ibuprofen, but both of those enhance my performance or psychology. So watch out, Wiggo, I'm gunning for you!