I think the thing with the US is that the Olympics air on a commercial tv station (NBC). NBC's main goal is to have big ratings so they can get good advertising rates. If they find that not enough people are interested in watching biathlon (or whatever), it doesn't really behoove them to air it. Compare Canada and the UK who air the Olympics on public tv stations. These stations are not wholly dependent on advertising revenue (CBC in Canada does have commercials but they get most of their money from the government; the BBC is supported by the government (and the public via their tv rates)). As such, they are somewhat freer in their programming decisions.