more acceptable to be killed by a human
Pilot error is a major cause in crashes. Automation basically kills less people. Therefore it is a reasonable design decision to to automate as much as possible. In the same way air bags can hurt you, but we require them to be fitted in new cars because overall the benefits outway the risks by a large margin.
The route cause is flying with bad instrumentation. Even if you fly manually, bad sensors can kill you. In daylight you can judge you angle of attack, height and speed. At night, or weather probably not. You have to trust the instruments. You can tweek the software, and pilot training, but that is larglying ignoring the real issue. The aircraft was not in a fit state. If you crash a car because your breaks fail, no-one asks why driving without breaks is not taught. ABS can help, but if you loose break oil or the pads are worn, or the tyres are worn, its a maintenance issue.