The main issue here is the meaningless murder. NPCs out that far should be looking to extort returning explorers, either for credits or a share of the data they acquired. That would justify them being there in the first place, and justify their actions towards players.
We can all make up fake excuses as to why they're killing players, but we're just deluding ourselves.
Really, until NPCs are put there for a specific reason that actually plays out, they shouldnt even bother interacting with players.
They should be extorting players. They could be pirates patrolling their turf, having a secret unsanctioned base nearby. They could even be hired killers there to specifically target explorers who are selling data to a rival faction. Either way the reasons should be clearly identifiable by the player - because non-interactive and nonsensical reasons (like drop your non-existant cargo) do not make for interesting gameplay, and just leave players frustrated, confused, and downhearted at the lazy gameplay 'feature'.