This is a poor ass excuse broskie
No, that's really the main reason or should I say part of the reason there's fighting in the NHL. Trust me I'm a long time hockey fan, been one since I was five and played since I was seven. Say for instance some big lumbering defensemen comes and slams your star player into the board, there's a good chance someone will go up to that defensemen and at the very least start shoving him around for hitting the star player. And it could very well escalate into a fight. Sometimes if a player hits a rookie, the rookie's teammate may come over and harass that opposing player and that could result in a fight. So it's used to enforce "law" which is where the term enforcer comes from.
But sometimes dudes just fight because they're pissed at one another or maybe they want to give their team a spark if they're losing.
I'm not saying its a good or bad reason, but there it is.
Anyway, there's been increased chatter over the years about is fighting even necessary in the game and perhaps it should be taken out. In the European game you'll get ejected automatically for a fight I believe. It's just the NA game where you get your five minutes penalty. But the European leagues are less physical due in larger part to a larger ice surface.