As memory serves all players are part of the Pilots Federation, NPCs are not so an in game division exists, although their lethality is identified in the same fashion and initially FD did not want to promote ‘griefing’ as a game mechanism.
Lore wise stations etc issue missions only to PF members, because they want a trusted service in a frontier environment and that is what the PF provides.
Technically lore wise you can be invited or apply to the Pilots Federation but game wise you cannot be booted out. FD initially wanted to discourage griefing through PF bounties and wing escorts, but like many core elements in game, like exploration, piracy etc they never applied anything and what we have is a lazy compromise.
I don’t believe FD will ever apply this, but how about 3 strikes and you’re out?
Kill a clean Cmdr who isn’t aligned to a power, or doesn’t have an open bounty etc and current law and order still applies, but after a certain number of such kills the PF issue you a warning, any continued infraction against PF members and your membership is then revoked.
You can still play the game, and still kill Cmdrs but all permit areas are now locked out to you; you loose the option for any insurance; community goals (mission not location) are locked out; all missions, PowerPlay, war bonds, ships, modules, foot based areas which are linked to PF membership are locked out too except for those in anarchy space or pirate controlled factions.
This wouldn’t stop certain behaviour and likely will actually encourage it, but it would now have context and introduce additional grind which might discourage certain behaviour by engaging the player to play the game rather than prey on easy targets eg other players who have more to loose because time is the predominant currency in game.
If a player wants back in to the PF they can re-apply but have to go through a long protracted PF application involving various non lethal humanitarian missions (!) or gain XP through policing or military service.
And of course FD would need to fix piracy and actually build a robust piracy based game loop that is attractive to players and not the piecemeal we currently have.
Generally this whole conversation is due to a game mechanism gap FD never resolved and behaviour they didn’t comprehend, players with an absence of engagement misinterpreted this and exploited it, which is only logical.
In the end such activity is marginal and FD just want the easiest route, so group / solo / ban is the default method of avoiding such activity and it works to a degree.
It would be nice if FD fleshed this game out more but don’t hold your breath.