Actually I admit playing solo for the only reason I perfectly know that a player might want to just shoot me for no reason besides his own fun...
The thing is in ED the player can actually shoot you in any system almost with no quick immediate answer from security...
Shooting at peeps should be only a non security response in anarchy and war (add to that civil war area) and then on all others system than that, immediate security intervention.
That could lead all of us to really PLAY the game instead of playing the "Cr/h" only or the "I want to shoot someone" only...
Pirates then would need to gain more anarchy systems through missions (and so yes they will need to actually play the game) and same for those high revenues trade routes where the haulers would need to complete missions as well to keep their route in non anarchy systems... add with that that I think AI should be way more aggressive into anarchy systems as well so even the solo player would need to help secure routes doing missions...
Pirate AI could as well gain anarchy systems, as well as a counter from controlled systems gaining their... but for that to really works it should be a fairly decent changing speed in systems authorities so every day a trading route could become dangerous, needing players to adapt and either work to regain security on that efficient trading route or find a new quieter route
Also could add that security would help the player in danger quicker if he actually have an allied status (or any better status dunno if that exists) within the system he's attacked... so again would need more work to get better help, as well as a pirate could gain some kind of immunity, paying authorities (hence lowering his incomes) or completing some missions to get more time before security actions...
Only my 2 cents on that, but I feel that this way we could all really PLAY a game more than just grind for the next ship or have fun destroying other's ships...