Overweight, crew were aware of the fuel situation, discussed two refuelling stops, and didn't advise ATC even with two engines out.
As stated by many of us this "accident' was clearly a result of a macho, rule-averse crew working in an inadequately regulated and nepotistic environment who lacked the "professionalism" (lower case intended) or judgement to even declare their error when it must have been clear that it was of fatal proportions.
As the engines began to fail they clearly had the altitude to glide directly to the field yet declined to do so, preferring to pursue a fatal 3-dimensional flight pattern that saw them squander their glide range immediately in a max-drag descent that ate up no distance to home in order to capture an utterly inappropriate glideslope that was clearly only attainable to a powered aircraft, but not a glider.
With all the pre-flight showboating, big I AM pics, and load of high-level high-living pax could they have been partaking too much of the cabin fever that surrounds such prima-donnae - Peruvian Marching Powder perhaps? I can't think of anything else that would make sense in this most senseless of crashes.
How else can you rationalise deliberately flying beyond your available range, deliberately passing en route fuel stops, deliberately arriving at destination with a fraction of required fuel, deliberately going into a hold and saying nothing, losing engines due to fuel starvation and STILL saying nothing...
They clearly weren't in their right minds. Given the nature of the pax perhaps recreational pharmaceuticals played a part?