You need superstars. Ask Toronto and Cleveland how they are doing without their star players?
Star players make the game easier for their teammates. Teammates don't have to force their game and do something they don't have the skills to do.
Bargnani is not a building block. After five years in the league, we know what we have. We have a player who has no commitemnt on the defensive end, and who wants to just take take shots. Its time to trade the chucker.