If you look at the events in the Winter Olympics, you will see a ton of individual sports. Even within the individual events, it seems to matter more about the person who won rather than the country.
Hockey, bobsleigh and curling are the important team events.
Beyond those, figure skating and speed skating are semi-important to countries, though they feature singles competitors (speed) and pairs (figure) rather than teams.
There are more team competitions during the summer.
Archery, badminton, basketball, gymnastics, rowing, sailing, volleyball and soccer earn medals for an entire country.
But when Michael Phelps wins a gold for himself in an individual medley competition, it feels more like he's earning one for the entire United States as well.
Snowboarding doesn't have the same effect.
The nature of the events calls for closer finishes. The amount of events provides more medals, more wins, more competition and more importance.
It doesn't matter if the United States loses ski jumping. It matters when they lose a swimming relay, though.