I had a (possible) theory 8 years ago and I still stand by it. He maybe(just maybe) wanted to land on Christmas Island(which he frequently practiced on a simulator) and he went around to be so far from the radar and air traffic (which correlates with pings) and then failed because he was under pressure in cabin from other pilot/passengers or just lost the nav or what not, even the drift data supports this (the parts that washed ashore on Madagascar). Of course I don't think it IS what happened but just a possibility that's not being discussed because people are so convinced that he performed suicide just because of that. It's crazy how dark thoughts prevail in people's minds that they can't think of anything else.