Have you ever played poker against an opponent who goes out of his way to make it appear that he has a strong hand? He tries to be quick, confident and as intimidating as possible. You decide to fold your hand figuring he has to have something. But it was all an act, trying to look tough to get everyone else to fold, he only had rags. Strong means weak, weak means strong. That's how the Bucks are operating. They want to appear that they are in a strong financial position to all outside parties, renouncing Villanueva, dumping Jefferson. "Don't even think of messing with us our only goal is matching Sessions punks!" But they are actually in a weak position, with one of the lower revenue teams in a small market with a poor owner. They can't afford to pay an upside guy like Sessions major dollars when he isn't a proven player. They know it will be bad in the long-term to pay a guy the 2nd or 3rd most money on the team when he would only be the 5th or 6th best player of a playoff team. They don't have the luxury of Paul Allen. They're just hoping other teams guess wrong and nobody offers Sessions above the MLE over the life of the contract, because that is the only way they can afford to keep him.
