Been thinking about this overnight and wanted to share my sober thoughts on this clear but cold day.
I agree that murder appears to be a valid option from the players point of view, however there are ramifications for it in the protagonist as FD apply a wanted marker. So I guess it is something that it accepted, but not encouraged.
If I had a gripe, or a fear for this style of play, I'd equate it to what we have seen in other open world multi-player games. DayZ & WoW are two that spring to mind where they haven't handled sociopathic players very well, thus the game descends into an endless spiral of ganking and reprisals.
Perhaps I'm hoping for a mature approach to ED and I reiterate that can be a place for such unwarranted actions, but I hope ED keep the penalties for such actions in focus, perhaps even having the police responding to such events at the interdiction point. I feel like I need to qualify every suggestion as I can anticipate the vitriol that such a suggestion would bring. If the police response wasn't guaranteed, obviously only in systems that have a government and the randomness of it to indicate that the police can't responding to everything (unless it's one of their own who gets hit, then the whole galaxy patrol turns up).
Anyway, tl:dr, murder - yes, but limited and not without repercussions.
Someone suggested the PvE group and another said "the game would be boring without pirates" you both missed the point, he/she wasn't pirating. I don't mind pirating, I like the RP of it.