I guess people just seem to find innuendo, conspiracies, deceipt and the darker side of human nature far more interesting than the 'good' and wholesome.
Sad, isn't it?
Cycling doesn't feature a lot in the mainstream media when the Tour isn't on. That was largely down to lack of interesting English speaking riders. There waas a rise in interest in the 80s with Millar, Lemond, and various Australians, then in the 90s with Boardman, but Lance took it to another level, partly down to the human interest angle. He was a meal ticket for the cycling media, now that Wiggins has won we can discard Lance.
I monitor some of the UK media for cycling coverage.
Often, even when a UK rider has done well, they give greater prominence to cycling doping stories, even when the alleged doper isn't British or isn't well-known. However, they rarely mention the vast amount of doping that goes on in other sports, not to mention the match-fixing, diving, arguing with the ref, drunkenness, sexual misbehaviour and recreational drug-taking that is commonplace in most games.
Why do we want to add to this prejudice against people who ride bikes for a living?
