I apologize if this has been answered. It's late, but has anyone addressed the issue of the current search area being nearly 180* degrees in the wrong direction?
There's been talk of a "zombie plane" (i.e. - crew/passengers incapacitated/dead and the AP just continuing on it's merry way). However, in such a situation, is radar coverage in that part of the world really that sparse? That a modern airliner can fly undetected?
At the same time, most (if not all) ATC relies on the transponder to be functioning and broadcasting to be able to pinpoint position. Although looking back, on 9/11, weren't the transponders turned off, however ATC was still able to track the planes on return pings alone?
Either way, it seems as if something went terribly wrong, terribly fast. Otherwise there should have been at least some sort of communication indicating trouble.
OR, something was done intentionally. I initially feared mid-air breakup due to bomb (first initial guess) or structural failure (far 2nd guess due to the the service record of the T7). However, if there was data (attempting/available) for transmission for such a long time, it seems as if most, if not all, the occupants were disabled within a remarkably short amount of time, or someone intentionally didn't want to be found.
Of course, the latter points to either suicide and/or terrorism. However, people generally, but not always, leave things behind for others to find after they commit suicide (sadly, I'm familiar with this). And terror groups of any size would (I'm guessing here, so please don't chastise) love to claim responsibility for a disaster/mystery of this scale.
Which points to either a (absolute) lone-wolf-type terror event, or a highly unforeseeable event that caused incapacitation very quickly. Personally, I'm leaning towards the latter. As in, 89* lean towards the latter.