why they didn't fly a LOC approach or VNAV as only G/S u/s if they were so concerned about a visual approach and its perceived problems.
This has been asked many times and never explained. The Asiana pilot said he was very stressed over having to hand fly a visual approach w/o ILS glideslope in CAVU conditions. If so he evidently had two options: (1) use the published RNAV/GPS approach or (2) use the FMS VNAV system.
Further unexplained is since the 777 uses back-driven thrust levers and they were not moving -- sitting at the idle detent (where the pilot put them) why the surprise over low thrust?
It's ironic this accident is commonly attributed to "automation dependence", when in fact the pilot did not understand how the automation worked. He wasn't over-dependent on automation which failed, rather he didn't understand the automation, plus failed to use available automation modes, plus couldn't hand fly a visual approach. That was not a good combination.