It's pretty well documented that Derozan spends a lot of his time in the gym working on his game. Some people get motivation from different places. He was already a good player, multiple ASG appearances, being a top two player in a team that reached the NBA conference finals, and then a dumb ranking from a well known magazine comes out and says that he's only just okay is enough to make someone pretty mad. If that gave him an extra boost to improve his game, then great, no one knows if this would have happened regardless since DD is always working towards improving.