The reason, of course, is the oft mentioned clause in his contract known as the “Rose Rule”. If a player is named to an All-NBA team twice or MVP, or voted in as an All-Star starter, then the first contract they sign can be up to 30% of the salary cap, instead of 25% of the salary cap. The Pelicans offered everything they could the day they could, and that included maxing his salary out if he qualified for the Rose Rule.
And he didn’t qualify. He was only a reserve for the All-Star game – and he joined James Harden and Paul Millsap as just missing out on landing on the All-NBA third team.