The problem is: all activity in this game exists to make the player happy. I mean: if pirates will always pick other targets it will mean 1 less challenge.
But!
1. May be its just me, but it is too obvious (lets be honest), that world spins around you, and it doesnt help you to feel like you playing an RPG.
2. Picking good spot where pirates will avoid you, but you will have opportunuty to make some profit, can be a good challenge itself.
Imo, if accessibility represents how hard to reach your world, and it affects your trading routes, it also must affect pirate decisions. I mean: pirates is a poor people with bad ships and pretty low ammounts of fuel. Why do they decide to strike system in opposite corner defended by 3 HQs? Or maybe they have money and just wanna see the whole world burn... Or maybe they are undead zombie horde...
Good points both. I must say, that by no means would I like PC bases to be unraidable by pirates. What bugs me is that if you want to take down the slaggers, you need to get a ton of fuel and trek through the entire sector, just so you can say hi and unleash all kinds of weaponry with extreme prejudice. At the same time, the length of the trek does not seem to affect the pirates in any way. So I'd just like to have closer pirate bases mug my colonists.
Also, the location of the bases is somewhat strange. The moment my screenshot was taken, there were 2 known pirate bases. One at Yamaros' Work, and the other at Xaphassor. The first at the other end of the sector, the second just about next door. Now one may argue, that the pirates aren't an unified faction (which is absolutely true) and as such will loot and raid independently, but with this behavior I am inclined to believe, that they indeed want to see the world burn. (Or are a zombie horde, as their supplies/fuel would surely dry up before reaching me otherwise.)