"When people riot, they are rioting because of an existential lack, whether they know it or not. Nobody really cares that much that the Canucks lost to the Bruins in Game 7. Further, nobody believes that rioting will change the outcome or even make them perform better next year. Whether they know it or not, they are rioting so that they can experience something with absolute ownership of the experience and their actions. It’s a reaction to life, not to the game.
The reason that this particular riot happened to coincide with Game 7 of the Stanley Cup Finals is simply because it could.” - icarusone
The people of vancouver are rioting because they feel something is lacking in their life and they want to experience a sense of realism and fulfillment, the loss simply gave them a reason.