No. Pruitt, Walker, and Giddens have all said that this is helped their game. This is a way for them to learn the game, stay hot in the game, and to advance their skills. The NBDL may not be as talented group of players as the NBA, but its still a step up from the NCAA and High School teams that they've been going up against for their careers so far.
Bill Walker at the beginning of his season in Utah used to just about foul out of every game, he'd score some buckets and rebound in the first half but was ineffective in the 2nd due to personal fouls, he has now righted that ship and has consistantly been a player that the Flash can count on.