So, why are you so bothered that just once in a while you may get attacked by a pirate that is NOT an NPC.... ? Why is that such a problem to you solo players.
Honestly i'm not trolling here, I am genuinely puzzled by this aversion to playing a space MMO in multiplayer mode...
You are puzzled as you are trying to place their perspective in terms of game mechanics. Instead, place it in terms of choice. Then, it's quite simple as you are not conflating two things that can be unrelated which can cause puzzlement.