this phenomenon only seems to happen at baseball.
To answer the question of why, it's worthwhile to understand that baseball is simply a higher class sport. Like golf or tennis, it appeals to those of higher socioeconomic status, just as Nascar and hockey appeal more to lower socioeconomic classes. As such, baseball is seen as more of a gentleman's sport, and its fans view themselves the same way, so they are generally more determined to conduct themselves in a gentlemanly manner.
I'm not going to argue that the victory lap was right or wrong --- just trying to explain.
This post was edited on 3/1 at 6:48 pm