Football's reaction is interesting because it is so at odds with how baseball reacts to when pitchers alter baseballs to make them move and, consequently, harder to hit. Like in football, baseball's rules precisely define the dimensions and weight of baseballs, and it's illegal to alter them. However, unlike football, when a pitcher's caught altering a baseball (scratching it, covering it in grease), the baseball world doesn't rise up in protest and call for games to be forfeited or pitchers be banned from the Hall of Fame. Indeed, Hall of Fame pitcher Gaylord Perry made a career of throwing spitters (a particularly effective way of doctoring a baseball). He even wrote a book about it (Me and the Spitter: An Autobiographical Confession), and no one is calling for his ouster from the Hall of Fame.
So what gives? Is baseball less ethical than football? Not at all. In fact, baseball became far more incensed about players using PEDs (performance enhancing drugs) than football ever did. Instead, there's a bit of arbitrariness to the ethical systems of different institutions, whether their sports-related or not. And they're rooted in the stories that they tell about themselves and how they define what ultimately is good and just and right. And that is why a particular individual can get all up in arms about Tom Brady doctoring his balls but not about Gaylord Perry doctoring his.