People were shocked when Jim Bouton revealed rampant amphetamine abuse in Ball Four. People wanted to be just as shocked about Juiced, but anyone who claims to have been is either lying or an idiot.
Steroid use by East German swimmers in the Olympics was such a given as long ago as the '70s that jokes about it were very likely Johnny Carson staples on The Tonight Show every four years. Ben Johnson over Carl Lewis was way back in 1988.
Jose Canseco and Mark McGwire instantly became baseball pioneers in the late '80s by challenging the accepted notion that lifting weights was a harmful training activity for baseball players. Conventional wisdom had always been that weightlifting would by ruin a baseball player by robbing him of too much flexibility. There were a million articles about it back in the day and almost every single one pondered whether Canseco and McGwire were using illegal drugs.
As Claude Rains said in Casablanca, "I'm shocked, shocked to find that gambling is going on in here!" As Claude Rains also said in Casablana, "Round up the usual suspects."
Bill James’ article mostly deals not with the present day, but with how things will look in 40 or 50 years. My guess — and James seems to agree — is that by then Jose Canseco will probably look a lot better and Bud Selig and the other so called custodians of the game a whole lot worse.