The simplest possible solution with the facts that we have now is that one of the pilots (one of the pilots wife and children moved out of the family home the day before liftoff) wanted to commit suicide (taking many victims with him), but for some reason wanted to leave a mystery. Perhaps relating to insurance in some way -- hoping the black box would never be found that revealed any of the actions. Their tactic might have been to continue flying into no-return range in such a way that they didn't have to fully admit to what they were doing until it was too late.
It is terribly crass to make someone a villain when they might have been simply a victim, but of all the possible explanations that is all that seems to fit right now. That someone wanted to leave a mystery, and intentionally crashed in a place and way where it was incredibly unlikely that they would ever be found, and it turns out that only a communications handshake and some technical excellence led to it possibly being found.
This particular rumor is less vicious that the ones about him being a political fanatic, or a Muslim extremist, but no less sad a reflection of how far the press has fallen.
What bugs me is just one point that is not fact. Would you consider reading this: - an NYT story on the pilot's background and how it got twisted out of shape by tabloids (http://thelede.blogs.nytimes.com/2014/03/19/pilot-of-missing...), and - a WaPo story with a named source who clarifies that his wife "moving out" was her normal practice of staying with their grown children whenever he flew (http://www.washingtonpost.com/world/agony-mounts-for-familie...)
- and see if it changes your point of view? or at least, how you might describe the pilot's state of mind the next time you share your thoughts?