Risk management
Having a little experience in the risk management area in aviation, plus a history in PNG, I cannot allow trhe previous comments to go unchallenged.
Risk assessment is a developing science, particularly in aviation. It takes into account a wide variety of threats, but also considers appropriate risk control measures. The purpose of risk assessment is not to find excuses to avoid certain types of operations, but to identify threats and apply appropriate control measures.
High risk activities take place in aviation every day, all over the world. Examples are ETOPS (a classic risk assessment strategy; considering the probability of an engine malfunction), ag flying (particularly night spraying), helicopter logging etc.
APNG have I am sure carefully considered the risks involved, and applied appropriate risk controls. These can include training, technology, techniques etc.
Nobody, but nobody, "accepts" an accident, nor are they as blase as you suggest about the loss of life involved.
The reasons that accidents occur in PNG are the same as the reasons they occur elsewhere; a compromise occurred. Sometimes that is due to human error, sometimes mechanical failure, sometimes due to external factors.
Flying in PNG remains no less safe than anywhere else - the environment and the procedures must be understood and respected.