Ladies and Gentlemen . . .
Most of the speculation here -- including many of the "informed" comments of professionals -- is simply "by guess and by golly" based on everything from google to gut feeling to real-life experience. At this stage even most of the best informed and best intentioned of posts should be treated the same as the genre we now call "creative non-fiction". In no case should anyone assume that what we have learned so far points with any degree of accuracy to the "cause" of this tragedy.
The best that we can hope for is that the recorders will be located, the data decoded, an informed report issued, and aviation safety thus further enhanced. I for one have a high degree of optimism that these things will occur in this instance.
Grizzled