Because lawyers know the the main culprits that created the problem can't change their behavior. Bravado talk, inflammatory accusations, defamation...all of it is part of their culture and what created the grounds for the lawsuit to begin with.
So, note to Jean Carroll. this is how a confidentiality clause worked in my community, and might help you teach this immature man a lesson:
The mayor of our city had a major profile in the legal complaint. The settlement agreement saved his political ass. When he went to run for reelection, he had an ad which listed his accomplishments. One of the things he claimed was, "We got rid of Jim Mikes" (The developer who elected and community leaders tried to run out of town.) For that, Mikes sued again and the amount paid to him for breaking the confidentiality clause was either 50,000 per the City's claim or $600,000 if you believed a campaign ad from another elected official who ran against him.
That's who the confidentiality clause was meant for. The loud mouth braggarts who are stoking the hatred and creating a movement that defies the rule of law.