First off, it was probably one of the worst trades in NFL history. Revis was one year away from unrestricted free agency. He couldn't be franchised. Despite knowing this and the fact that he was fresh off a torn ACL (which we never saw him fully recover from and there is no guarantee that he has) the Bucs sent a 1st and 3rd round pick to the Jets for a guy, that if they just waited a season, could get with no compensation. Then they take Revis and sign him to a contract that is far above his free agent market value. Think about what CBs were getting paid last season in unrestricted free agency... $5 million a season for some really good CBs... and the Bucs gave him $16 million in addition to giving up the 1st and 3rd for a player that wasn't fully recovered from his injury. That's three negatives right there, Compensate player, compensate Jets, guy isn't healthy.
And it isn't that we need the money, we need to spend our money more wisely. Good defenses are built on the backs of their front 4, not the DBs...it's never been done that way successfully. Great defenses have great defensive lines... and you can't have a great defensive line if you're giving up elite QB money to a CB and you're giving up premium draft picks to do it.
In a good defense, a great DB is a want, a great pass rush is a must-have. That's why Revis has to go.... want vs. need.