When any plane crashes in a remote area it is missing initially. Unfortunately I expect this will be found in the desert sometime in the next 24 hours. It is the media jumping on the plane missing bandwagon to try to make money as it is more sensational that another airliner has gone missing! In 2012 there were 24 transport category aircraft crashes, 20 of them involving fatalities. Unfortunately it is not that rare of an occurrence, at the present time, people can make money as there have been a couple of high profile ones so interest is up and papers will sell.
If this was for example the Hewa Bora Airlines 727 that crashed in 2012 killing 70+ it would not sell as many papers so most are probably unaware of it, or how about the Iran Air of the same year killing 77, also a 727. Would not sell papers so not headline news.