[irishcoffee]

I don't have a source, but possibly a rationale you might agree with: It tarnishes records.

Mark McGuire destroyed the home run record, and then it was discovered he was using juice. Would he have broken it either way? Maybe, we'll never know.

You can argue that baseball stadiums shape changes over time, bat technology changes, we learn more about nutrition and training, etc. and they're valid points. That should be how records are broken naturally. It diminishes the achievement, to me, when those before you did it naturally, and you did not.

Would lance have won that many tours, and in a row? Maybe, but now we'll never know, and its a record that may never be broken naturally. Yes, I realize its not actually an official record anymore.