The issue is also squealingly excited local administrators handing out information, be it true or false, and obfuscating the picture.
Of course, a hijacking would potentially fly over the peninsula - but I'd have thought it wise to send a couple of F18s (they have them) up to have a wee looksy. Y'know - invasion of air space and all. But no info on that. Really only 300kms over the Malaysian landmass, what, 30 minutes flight time? Who'd care, right?!
In general, I'm thinking either (1) this is a monumentally cocked up search effort, or (2) there is some kind of live situation with the stakeholders engaged and the rest is smokescreen.
I fly in and out of KLIA, so have a vested interest in hijackings, false passports etc not happening in the region.