Because the qaulity of play has gone down. Since Jordan and company (Hakeem, Barkley, Ewing,etc) retired b-ball has been stale, it features overpaid athletes (Lebron included) that don't have the skills to match the 90's. Hell, The US dream lost, and some of the hottest b-ball is in Europe not the US.
If you ever have watch any AND1 videos, it shows that most players now focus more on dunks, have no love for the game the fundementals on winning, just spectacular dunks and shots, showmanship.