As a society we enjoy the spectacular. It makes our own lives seem somewhat less humdrum. Barry Bonds crushing 73 home runs. Shaune Merriman pulverising the QB. Tiger Woods driving a par 4. Since society so amply rewards those capable of holding our attention with these type of physical feats, athletes will use every opportunity to improve their performance unless they are specifically outlawed. I worked on an anti-drug campaign aimed at Australia's elite athletes before the 2000 Olympics. The stories I got from household name gold-medal winning athletes would make your hair stand on end...
The MLB players association has been the strongest labor group in baseball. Remember the '94 World Series? Neither do I. The very next year as the teams recognized they needed to make it up to the fans, the game got a lot more... 'spectacular'... and a lot more profitable... the fans were happy, the players happier, and most of the owners even happier.
I'd term it "who wants to kill the goose that layed the golden egg".
They only acted because Congress was threatening to step in.
I agree. MLB has known about the problem for decades and chosen not to intervene because they thought it would be better for the league and/or because they didn't have the gumption to challenge the player's union (note: No. I don’t have the documentation to prove this definitively. I APOLOGIZE FOR OFFENDING ANY FORMER DEBATE TEAM MEMBERS.) They act now because of congressional pressure.
For MLB to penalize players who took performance-enhancing drugs during the time period before the league began testing for them (condoning them in a pragmatic sense) would be hypocritical and unfair in my opinion. Many players had to take drugs to compete for their jobs because MLB never stepped up to the plate on this issue. There's no way of knowing how many players deserve asterisks on their records over the last few decades.
MLB now has the chance to tackle this issue properly, and I hope it eventually will. Harsh penalties for offenders, public education of the health-related (Lyle Alzedo) and legal/professional consequences (Marion Jones), and a more balanced focus that targets growth hormone and amphetamine use are needed, for starters.
It would also be nice if Jose Canseco stopped trying to write books that claim steroid use is healthy if used in moderation. Perhaps Governor Schwarzenegger should write a book about the cardiovascular maladies he sustained.