People have becomes fixated on quick fixes. I blame shows like NCIS and CSI, where every fact is nailed down or positively identified by the magic of technology and science within the hour, each week.
We forget the size of the earth, physically speaking. We forget how much of the planet is hostile, or desolate, or simply empty of human infrastructure - difficult to get to. We forget just how limited is the search response - just the other day it was as little as 12 planes, eyeballing vast stretches of water and uninhabited land, searching areas as vast as the continent of Australia.
We forget that satellites are positioned for navigational purposes, GPS, broadcasting and military so are mostly positioned to see populated areas, not the more desolate regions.
And trying to fly and unscheduled, unexpected jet into the airspace of any developed country will be picked up pretty quickly, I think.