I see your point, but I love when kids love what they do on the football team and feel comfortable enough to express themselves, even if it seems over the top. Love it for BYU players and love it for other teams.
Only exception to that is if it is at the expense of other people, if it is selfish, tears down others or if it turns into dirty play. I don't like that type of extremism.
I love the extreme joy, excitement and celebration. Go crazy celebrating with your team, be a little over the top. That is great and is a part of the entertainment we call football. Don't taunt people, don't be a dirty football player and I love it.