case in point: Tyler Herro won 6th man two years ago. He played 32.6 MPG, tied for 3rd on the team and equal to Bam - a full time starter. He also led the team in FGA per game.
69 players in the NBA started 50 or more games and played less minutes per game than Herro.
IF the design of the award is to reward bench role players, not the main contributors, players like Herro shouldn't have been eligible.