What people complain about isn't inherently the players; it's douchey to obliterate undefended players, but that's not the fundamental problem. If that happens in an Anarchy system, for example, it's not an issue.
The problem is that it makes no sense in what is supposed to be a realistic universe. If a pirate obliterates a helpless trader in a high security system, there would be outrage from the local population. That person would lose their rights to use that faction's facilities for years, and should be chased and interdicted constantly by the local police, with more and more ships chasing them until they run away, and even continuing to chase them for a ways out of the system. If that player kills someone in a permit-locked system, they should instantly lose their permit. No second chances, they're there by permission, and that permission should be gone.
There's a dramatic disconnect between the supposed rules of the universe and what actually happens in gameplay, and every time that disconnect is highlighted, it brutally rips the player out of their immersion and back into the reality of a poorly designed game.
If players could lose their Shinrarta Dezhra permit, they'd be a LOT more careful of what they did there, and the permit and security ratings would actually mean something.