I can totally tell you know know nothing about hockey, not necessarily a bad thing. But you are lacking the reasoning and understand as to why there are fights in hockey.
Hockey is a totally different animal then any other sport. Baseball, soccer, and basketball don't count because they are not physical sports, that involve grown men crashing into each other. There is no room for fighting in any of those sports.
Like I said hockey is a totally different animal. Imagine having a stick, and being able to complete fuck up another dude on the soccer field, without having a red or yellow card thrown at you.
There is way to much opportunity to get under someone skin with hockey. There are many different types of players in hockey. There are players that sole job is to annoy, heckle, and just plain mess up any offence that the other team is trying to achieve. With that being said in football, each play is stop and start. After each play, the play is dead, and the game goes into sort of like a time out. In hockey there is no stop and starts like that, only by a goal, or a ref whistle. Like I said in hockey you have many different types of players. The superstar goal scorers like patrick kane, the mean two way forward like Marian Hossa, the massive defenceman that will fuck your world up in 2 seconds Zdeno Chara. There are too many opertunities to mess someone up, in hockey which is the reasoning behind fighting. If some dude on the other team takes a run at your superstar, then it is responsibility of the enforcer on the team to go fight that dude, or whoever on the other team. This makes players think twice before decking someone.
And next time that guy is on the ice, he will be looking over his shoulder, or may pull up before he hits one of your players.
Fighting also gets teams going. If your team is down lets say a few goals, getting pounded physically, being beat to lose pucks. Through out your enforcer to fuck someone up, really gets your team going, and makes the other team think twice.