It seems to me the most plausible explanation at this point is a hostage situation, not a mechanical failure. Where is the debris? And it can't be a heist to steal a plane. Oh, it's gonna be easy, we just need to kill 250 people, no big deal. There must be easier ways to get hold of a plane. It seems media has ruled this out on the basis "there have been no ransom demand". But there will be. I'd say within a week. Occam?
Why would they wait two weeks? That's a long time to wrangle 250 people. I would expect the ransom demand while the plane is still in the air, if only to contain everyone.
No reason to think we'd be privy to a ransom demand, for that matter. The appearance of bumbling incompetence on the Malaysians' part may just be a facade.
