Imo thisnis ppp psychological bunk.
Id rather players remain clam and focused on their jobs than being emotional trainwrecks. They couldnt perform as pros otherwise
this. Players aren't fans of the team they play for (even JT, Spezza and Marner arent) they are professionals who (hopefully) care about pleasing the fans, and not overreacting to a win or a loss and almost robot like moving onto the next game is the best way to do that. Unless of course its a playoff series loss then that's when they should be upset about a loss