It's almost impossible to speculate here without veering into the sort of discussion that upsets Warb ergo my twinning it with conspiracy theory thread.
In the previous instance of a plane fitted with a transponder and GPS tracking vanishing without trace.
The main theory kicking around was the plane had been flown somewhere and sold for parts and the two poor unwitting accidental passengers were probably bumped off as they didn't seem to have the access or skills to switch off the equipment or fly the plane away.
We have a couple of people flying on stolen passports.
The possibility that it might be a reprisal after the events of last year.
We have a semiconductor chip experts on the plane with the millions that could worth.
The pilot was previously reported as being an average nice guy who would go out of his way to help everyone and known for being so enthusiastic about his job he openly used flight simulator programs at home and flew model aircraft. Now he is labelled as 'Fanatical' because he was photographed once wearing a slogan Tee-Shirt and the already known of home sim set up is reported as elaborate and 'uncovered in a search'.
And yet these things can be piloted remotely.
Speculation is justifiable, not all crimes are carried out by lone crackpots but by the nature of the information available these speculations will be along the same lines as conspiracy theories and a little bit of ignorance can go a long way to hysteria.