I think superstars see other superstars thriving with less glamorous franchises (Cleveland, Golden State, OKC, San Antonio), and feel less need to go to teams like the Lakers.
Plus they see how things went south for Dwight Howard, which I think hurts the Lakers a bit.
Plus the Buss kids are not running the franchise like their dad did. It's just not the same anymore.
Stars will go where they can win and where they can get paid. You can win anywhere. And with the salary cap, the Lakers can't pay free agents any more than any other team.
This is coming from a Laker fan. So I hope I'm wrong and that you're right...