I might be over-thinking this...

But I get this distinct feeling that the main point of Slap Shot was to actually ridicule Hockey and point out how silly it is how everybody takes it so seriously.

Reggie as a character is consistent with this point. Talking to the team owner, he can't understand that hockey is a business that exists to make the owner money, or that an owner would buy the team for purely financial reasons. He also can't understand that no matter how successful he is in hockey, he won't be any more successful with his wife or any other part of his life. The condescending look that Francine gives Reggie as she drives away says it all, basically suggesting that Reggie is so wrapped up in his silly little games that he will never understand why she is really leaving him.

Second, throughout the entire movie, different characters discuss all of the hockey players who dedicated their lives to hockey and lost everything else because of it. Women walking away is discussed as a common occurrence, but there's also the drunk at the start who looks depressed and broken, and the fact that none of the players have any kind of back-up plans for life outside of the game ("hello steel mill!"). It also caricaturizes the players as man-boys who just want to have sex and fight - there's Mo, who keeps spouting disgusting things, the Hanson brothers who are literally children stuck in men's bodies (as seen with the toy cars and mommy issues), and Reggie who just can't seem to grasp the fact that success in the game of hockey doesn't translate into success in the rest of life.

There is also the fact that all of the fans show up once the team starts punching faces instead of actually playing the game. If hockey were such a serious, sacred sport, then why wasn't the team selling tickets before? This point seems to be punctuated by the fact that the only player who accepts the fact that hockey is just a farce put on solely for entertainment has everything go his way in the end. First he puts on a ridiculous strip show with the biggest happy grin on his face, then he wins the entire championship for the team, and then re-claims his wife and has the happiest ending of anybody in the movie. In other words, it seems to imply that the only real winners in hockey are the ones who realize that the sport is just a game that is meant to be played for fun.

All of that said, I am definitely one of those people who puts in way too much time following my home team, so I'm not saying this due to a bias against the sport (I freakin' love it!) That being said, if Slap Shot was trying to celebrate the sport of hockey, it did it in a very odd way.