"The situation wasn't right for him" can probably be used for a ton of players in the NBA. How often do guys get traded and then thrive, or tank there?
Hell, you could say the situation wasn't right for JR Smith in NY. He gets traded to the Cavs and fits right into a winning situation.
You could say the situation isn't right for Kevin Love in Cleveland. If he were traded to a different situation where he was the #1 option his stats would explode.
The situation wasn't right for Mozgov in Denver. And on and on.
So duh, the situation affects the player.
Bottom line, it's up to the player to do the best they can in the situation they are in. In Dion's case he blamed the situation. That's never going to fly no matter where he is.