NFL teams have rivalries. For decades, the Miami Dolphins and the New York Jets were the big thing in the AFC East. Owners tend to have rivalries as well, and some of those can get downright ugly.
The NFL is a cutthroat business, so if an owner can create a buzz or gain a leg up on another owner, especially one in their own division, they tend to take it. That being said, nothing in the world matches jealousy, and it drives some owners off the proverbial cliff.
That is the case with Stephen Ross and Bob Kraft.