Air travel
would be the safest mode of transportation except for one factor: 99.9% of air passengers arrive at the airport in a car or a bus. It's the 45 minutes between my house and the airport that I find most frightening. Especially the time I drove down country roads to the airport at night without headlights, but I try not to make a habit of that.
I think what makes this case unnerving is that we have this notion that aircraft are continuously tracked and monitored while in flight, and that just ain't so. Fact is, even commercial flights are pretty much on their own for at least part of any ocean route.
It's only been 5 years since a similarly-sized aircraft vanished over the ocean. As with MH370, it too "just disappeared". It took 5 days to discover the wreckage, even though it was more or less on course when it went in the drink. It took 2 more years to recover the black boxes, and another year to piece together the sequence of events that led to the plane's demise.
What was upsetting about that incident is that a nearly-new state-of-the-art airplane (an A330) could be brought down by a single minor malfunction that made it impossible for the pilots to know how fast the airplane was going. Were they too slow or too fast? With a 50-50 chance of guessing correctly, they guessed wrong, put the nose up and stalled - while ignoring the audible stall warnings that were going off. The airplane literally fell out of the sky, remaining horizontal and slowly spinning as it fell straight down. Stuff like that isn't supposed to happen.
The bogus-passport angle will likely turn out to be irrelevant. Stolen passports are a big business in Malaysia. Those two guys were just following a long-established procedure for escaping Iran: go to Malaysia under a legit passport, buy a European passport on the black market, and then choose your destination in the free world. If you can get off the plane before the stolen passports are entered into the database you're home free.
The pilot-suicide theory is also unlikely. To intentionally crash a plane the pilot would most likely send it into a dive, which would have triggered an automatic broadcast to the monitoring satellites.
As for pilot error, the pilot was a veteran. More significant may be that the first officer had no time in a 777, only in a simulator. Cruising straight and level would be the logical time to let the new guy take over the controls and get some flight time under his belt. They don't simulate every contingency in those simulators.