The reason people are bothered by steroids in baseball is because, unlike other sports, baseball is still pretty much the same game now as it was 100 years ago. The field is the same, the rules are more or less the same, and baseball itself has always been sold as a sport of history and tradition. Who won the NFL Championship in 1927, or for that matter in 1997? No one knows, no once cares. Football isn't about history, it's about the present and the future. But almost any baseball fan will say that the 1927 "Murderer's Row" Yankees were possibly the greatest team of all time. And that's why the steroid scandal exists in baseball; because even though Barry Bonds doesn't play the exact same game that Babe Ruth, or more accurately, that Henry Aaron played, baseball has forever sold the illusion that he does.
History and records are the backbone of baseball. In other sports, they don't matter as much, if at all.