The Toronto Raptors load management ideology was pioneered by the San Antonio Spurs. Gregg Popovich and the Spurs have learned over the course of 21 (soon to be 22) straight post-season appearances and five titles that you shouldn’t focus on the regular season. The rest of the NBA followed suit.
During Tim Duncan’s final six seasons in the NBA, he only averaged more than 30 minutes per game once. Duncan only played 80 or more games five times in his career. Popovich was routinely fined for sitting his star players during nationally televised games. He felt that having his players fresh for a post-season run should take precedence over regular season success.