The league owns and operates the Hornets. Obviously, they want to sell the team. Hard to make that happen when the best player is shipped off to LA.
Honestly this move would've been smart to trade him, because if he doesnt sign an extension you risk having him walk at the end of the season, much like LeBron James did. If If you were a potential buyer of a team, would you purchase team knowing that your biggest star could potentially bolt for free agency at end of season or trade now to see what could be got for this player? Nuggets traded Melo/Billups and after the trade played their best ball of the season, arguably playing better without Melo.