Used to enjoy figure skating more using the older scoring method. Now it seems way too subjective, who does the most spins/jumps and some convoluted way they score. Sports taking place in a few minutes, like speed skating, bobsled, ski jumping tend to lend themselves better to viewing during the Olympics. Hockey games go on too long or cross country skiing takes longer than the time they have to broadcast. Constantly adding newer sports also doesn't lend itself to being broadcast as the shows can only go on for so long.
In years when the Olympics are held half-way around the world, the time difference also presents a challenge on what events they can actually show live during prime time in the US. Otherwise the results are already posted online before the broadcast takes place.