NBA Draft System causes moral hazard. Teams tank in purpose to obtain a high pick in upcoming draft. Yet it can force parity in the league. America has unique sports system that can't be found in other countries. NCAA leagues are as popular as professional leagues and produce high quality and nationally recognized players but they are not under contracts with any professional teams. While in European soccers, teams search and develop talents. These talents have to sign contracts with clubs that develop them .
Without draft system, NCAA players would be able to choose their own destinations. These players naturally would choose rich big city club. People point out that as soon as they hit free agency, star players will just leave their original drafting teams in free agency.
In my opinion, it all depends on teams' ability to handle star players and surround them with good players. When his rookie contact was up,Shaquille O'neill quickly left Orlando Magic for the glamor of Los Angeles Lakers. But Dwight Howard spent 8 seasons in Magic before he got frustrated with the supporting casts. Chris Paul spent 6 seasons in then New Orleans Hornets. Kevin Garnett loyally stayed in Minnesota Timberwolves for 12 seasons. Kevin Durant, Russel Westbrook and Serge Ibaka are still OKC Thunders players. David Robinson and probably Tim Duncan areSpurs for life. Hakeem Olajuwon and Yao Ming are Houston Rockets legends.
Salary Cap does help in preventing big market teams from signing any star players they want. In the end it's up to the teams to make the most of their fortune of having drafted star players.