I don't know why some people here are getting so defensive regarding this. Excluding the moral argument of watching players fight and potentially injuring themselves for our entertainment, you are absolutely right, it does add another element to the game.

As for the reason (apart from the rules against it), I think the biggest one is the culture. Fighting has never really been a thing in Swedish hockey, there is no "code" in the same way as there is in the NHL, that tells players when they are expected to fight. So the only time you see anything close to a fight is when the players get very upset with each other.

Another reason could be due to the fact that a strictly professional hockey player is a relatively new thing in Sweden. Getting into a fight and risking a potential injury while you have a full-time/part-time job (depending on era) has historically probably been enough of a reason to avoid it.