opinion
Having just retired off long haul 777 ops I second the opinion of possibly crew competency. Forget the race issue ; this is not a prejudiced view but an observation of culture.
Regarding visuals , I stopped encouraging my FOs to do visuals after long days. I had 2 cases where it was muffed it so bad I had to "help".
And these were both men with background but lacking in recency, and then add in fatigue issues . My fault as a commander to put them in that position.
Now throw in a 37 year old CA hired straight out of star fleet academy at 20,spends his apprenticeship before the mast in an autocratic society , a FO not encourage to even pick his crew meal , and then throw in a no aids approach. A lot of if s but a possibility. One more variable. A programmed VNAV blindly followed to the scene of the accident.
Food for thought.