As far as I know, it’s the only individual celebration that is actually a function of the game. What I mean is: Someone scores scores a goal in soccer, he or she can rip off the shirt, do cartwheels show off the sports bra, run around while shaking both fists — which seems like the official “Yay me!” celebration in European and South American soccer. It doesn’t matter. It’s not part of the game. Touchdown dances, of course, come in all varieties. They’re not part of the game either. Someone scores in hockey, and the game’s structure quite liberal about giving the goal scorer a little freedom to hug teammates and some time to celebrate self. The clock does not run in any of these. There is no direct contact with the action.*The subconscious understanding of this requirement seems like it could be the source of traditional baseball antipathy to drawn-out home run trots, watching the ball when it leaves the bat, and all of the other things that Manny Ramirez used to do - and probably still does, to be honest - whenever he hit a home run. Those who respect the game, it seems, make sure the ball is on its way out and then go into a trot that's fast enough to demonstrate that they remember that jogging out a dinger is as much a function of the structure of the game (to crib on Joe's phrase) as it is a celebration of achievement. In other words, a properly-placed home run trot is as much a part of good baseball etiquette as hustling down to first.
*There are other examples. One in-game celebration is the breakaway dunk.
But in baseball, the celebration is part of the action … you hit a ball over the fence and you are still required, by the rule of the game, to run around the bases to complete the play.
I bring this up because I just watched J. D. Drew's 5th home run of the season. It was more of a line drive than a fly ball and it had a low enough angle to the field that Adam Jones in center had a shot to catch it. In fact, he almost made the catch: the ball sailed just out of reach, over the wall in left center. On the replay, you could see Drew watching the ball as he ran down to first. Drew isn't much for displays of emotion, as we know, and once he knew the ball was gone he tucked his head down and completed his circuit without giving Jones or the wall a second glance. But for a moment, as he watched the ball sail towards the wall, it almost seemed like he'd put aside wondering whether or not he'd have to go a higher gear to stretch out a double and enjoyed the circumstances that allowed him to celebrate his home run by requiring him to watch it.