Fans have no clue if certain players are struggling to learn all the plays in the offense or if they are inconsistent in how they apply the team defense concepts. There are a lot more factors involved than just who looks good for a couple of minutes in a game. You also don't know injuries or mental states or any of the team dynamic on and off the court.

Only the coaches and players know everything and what each person is capable of and where they have weaknesses. If Pedulla comes in and starts scoring 12 points a game but also gives up more defensive points, or has 8 turnovers a game, people would question why he is in. There is a reason that coaches play the lineups that they do.