It can't be 'banned' entirely or the cheep-shot artists would ruin the game. Their always needs to be the ability of the players to enforce the unwritten rules of the game among themselves and the guys who would intentionally try to hurt another player needs to know that he's going to face worse than a few minutes in the box and a fine from the league.
Through the 70s and 80s, there were far too many players who couldn't skate worth spit, but could punch anyone out and only got payed to intimidate other players. Too many fights, not to enforce any 'rules' but simply as intimidation.
Not anymore. Yes, there are some real tough guys out there, but they can play pretty good hockey too.
Sorry, but the occasional fight is necessary just to keep the lid on and keep everyone out there 'honest'. Other sports have the same. A dirty player in football is pretty likely to get himself hurt before the game is over, and in baseball, there is always that high and tight fastball designed to keep guys civilized.
In hockey, I'm not seeing the bench clearing 15 minute fights that were relatively common in the past. There are still fights, but they are generally one on one and shorter than the commercial breaks.