I'm not sure. There is so much vast wilderness in Idaho, it's not too surprising, I guess. Last spring, I drove through the eastern part of the state (think DeOrr Kunz case area) and there were stretches of road where we saw no other cars for miles, no other people or structures, large areas without cell service, only satellite phones, and the weather can be brutal both in summer and winter, with the short "inbetween" seasons having big fluctuations in temperature. Part of the state are high elevations, but for some reason people don't always consider that when they might think of it when visiting Colorado, but not here (I guess Idaho also doesn't have "mile high" everything like parts of Colorado). So visitors getting lost I can see more reasonably than long term residents.
I reckon it's like with most everything in life--there are factors which play into making situations more or less likely, and the wilderness is pretty unforgiving.
Hunting season is either just beginning or about to begin, so that could play a part--hunting is both big in terms of popular, but also it's big business here--there are outfitter companies all over who take groups out hunting and whatnot, including "city folk" who maybe perhaps sometimes underestimate the vastness and harsh conditions. I don't know. I'm curious about the statistics now, too, though!