Since we have satellites in everyday use, why would the airline companies not be able to simply track flights throughout their course? Once the plane ascends above cloud cover, tracking the flight by satellites should be simple. If Google Maps can constantly take images of the Earth, why not constantly take pictures of flights on their flight path to ensure that they are on track?
It truly is bizarre, although it makes for great stories, and potential movies/documentaries/etc. It's completely insane to think that man can make it to the moon but we can't find airplanes lost on earth--granted, the ocean is very deep and very wide, but even so. We should be able to find them.
We have so much technology, so many monitors, radars, surveillance planes, black boxes, cell phones, locating devices and satellites and still we "lose" planes. I think this is more an indication of some parts of the earth that are still relatively unexplored. The depths of the ocean is unfathomable for us, and in fact we can't even get anything down to their deepest depths to see what's going on. It's an amazing idea that there are 1,000s of square miles that are unapproached, unreached...unexplored. When events like this happen it reminds us humans that we really are quite limited and powerless.
At peak hours, there can be over 10,000 planes in the sky at once. While it is undeniable that we have advanced incredibly technologically, the task of keeping track of all the thousands of planes at once from thousands of miles away within the confines of physical and economic possibilities is something that would be more incredible than the fact we don't do so.
Even with the advancement in technology aircraft can still be lost because nothing is 100%. Technology can be hacked and changed without others knowing which enables even a giant aircraft to be "lost". It is more and more unusual but unfortunatly it is still a possible reaction to flying over very large areas of uninhabited areas.