So many ignorant questions 56P!!
"It is obvious that the aircraft flew into terrain. Just why is the question?"
An FO without a GPS approach rating was sitting beside a Capt who was flying too fast and below the published minimum altitude step which is ONLY there to provide terrain clearance. Simple as that.
"Will the design of GPS approaches be questioned?"
The approach misses the terrain by the prescribed minimum according to international standards supported by CASA.
If you don't like flying efficient and safe procedures, don't fly at all, catch the train (just be careful of level crossings).......or..............follow the PROVEN SAFE procedure altitudes, tracks and speeds. Simple as that.