Finances is not a problem in this acquisition. The Jets can cut him at the end of the season with no consequences other than losing a 4th-6th round pick. The issue is why would you add a malcontent to a team that isn't going to the playoffs? He is not going to help win additional games that make you a contender. He's not going to sell additional tickets. He doesn't make the Jets that much better overall.
You've added a headache that has refused to play on more than one occasion, has a history of fighting with team mates and you have a QB that is going to struggle getting him the ball which is what sets him off.