Why follow waypoints if your only gonna spear it in
We seem to have two possible scenarios.
1. Go South - and presumably crash into deep south Indian Ocean where it may never be found.
2. Go North. Could crash, but more lily to be found. Could possibly also land plane for a future purpose, but only if there was a skilled pilot involved.
If it was the Captain, you would have to figure he realised he would be tracked. Perhaps not in real time in the middle of the night. But it would become clear over subsequent days.
So if the plan was to land (i.e. north), why go to the trouble to make clear that he was likely flying? Why specifically draw increased attention to the possibility the plane may have landed, and that getting the plane was the purpose? If the ultimate plan was to get the plane (or the passengers), why deliberately tip off the authorities that this was a possibility? Whoever ultimately wanted the plane would presumably prefer to draw attention away from the landing scenario.
Going South makes more sense to me. If you wanted to strike a blow against your country, having an internal person responsible is probably more devastating than being the innocent victim of terrorists who may come from elsewhere. How do MAS respond to this? If a senior trusted Captain did this, that is a major problem for them. I was talking to a friend in KL tonight. MAS bookings are down and people are cancelling flights.
I feel the plan was to go south. It is a huge ocean down there. It is very deep in parts. Rough seas and remoteness from land will make search very difficult. If you really wanted to hide the plane, that is as good a place as any.
Make it unlikely the plane will be found - not quickly anyway. At the same time, make people feel it was most likely an internal job. This leaves lots of deeply disturbing and unanswered questions. No assurances this couldn't happen again - how do you protect against this?
I believe that would be the most psychologically devastating option. And that is why I believe this is what has happened.