The power is gone so the captain don't see anything.
Click on image.
The captain is not on his way to middle of nowhere, he is on his way to Perth. The blackout in the cockpit kills the navigation, communication and transponder and it's dark! He goes up in hight first so he don't hit another plane(nobody can see him), he spend some time checking what's wrong, he can't find it, what to do in the dark with maybe only a analogue compass, very difficult.
The captain decides to go back to find the landing track, he drop the plane to 3600 meter but he don't see any light's on the ground, cloudy and dark. So the captain decides to go towards Perth where the sun is going up earlier and he knows Perth, Malaysia Airlines flies there every day and the captain had over 18.000 hours in the air so he been there before.
When the fuel is gone the captain try to sliding land on the water, that's why there are so big debris, crash landing no big debris, higher speed!
The captain missed Australia with approximately 5 degrees.