It is? I've never heard about any Oort cloud civilization in the OTU. If you want to introduce a whole new aspect of Life in the Far Future, that's up to you, but those are not the pirates I object to (except insofar as I don't believe in an Oort cloud civilization.)
Perhaps it's more of an American thing, given all the crazy people and their strange utopian communities that popped up all over America at the edges that makes it all more palatable to me. Indeed, the Pilgrims themselves were pretty much an escapee fringe religious group, as opposed to the economic opportunists of Jamestown.
The pirates that we Piracy-sceptics really don't believe in are the ones that show up on the ship encounter tables, lurking at jump limit of the world the PCs have just arrived at.
My pirate clans operate more like special forces, with very precise attacks planned out and a lot of intelligence/loose lips sink ships sort of groundwork beforehand, a lot less 'seat of the pants' adhoc piracy.
A LOT of the viability depends upon the rules one has re: inertia coming out of jump, how much of a sensor broadcast the jump itself is compared to normal ship detection, detection rules and how well all parties are equipped, how often and reliably pirates can set matching vee to minimize time risk without triggering boarding and/or confiscation/confinement, and the economics of patrolling and response.
Adjust those, and you adjust the probability of the encounters.
We have our doubts about the pirates from the Pirate career and economic viablilty of flying around in 400T ships preying on armed civilian ships, but those doubts are admittedly less solid.
Now that depends upon a different factor, the corruption and ability to have a market.
What made the pirate republic of the Caribbean possible was a combination of factors, but the largest has to be paying customers for the loot.
And a lot of those customers were American colonies, with participants involved at the highest levels of government.
So if you have worlds that are lower tech level and unlikely to be able to pay the 50-300% price hikes one has to for high tech goods (depending upon the system used to determine price), largesse from the skies in the form of goods at 40% cost likely seems like something worth risking for.
A large enough market, and you can pay for all that supply and crew and armament.
Not me! I'm sticking to trading between worlds. And if I were to deliver a cargo to a Oort Cloud habitat, I'd be jumping in so close to said habitat that I'd be under its guns and protected against desperate traders.
A wise choice, but adventure awaits the desperate.
A standard feature of most of my space habitats is the rock shield, essentially a maze of rocks and debris intended to stop frac-C attacks in their tracks by breaking up the object short of the station.
Means anyone showing up has to navigate the maze to get in or blow a hole in the rock shielding, and that station guns are going to be of limited range.
Not all use that system of course, among other things it's practically a neon sign saying 'valuable looting site here' and not good for 'don't look here Navy guys this is just an iceball' discrete facilities.
You do realize that distances in Oort clouds are such that there'd be no long maneuver drive trips and no possibility of intercepting any prey?
Funny thing about those longer distances- gives you more time to accel and decel. Week long several billion km trips are certainly possible. I understand canon says jump was first developed by the Solomani for outer system travel, so anything outside of the 'local' trips would be jumps.
As I indicated before the Oort is a vast arena that makes pirate bases eminently possible, but that short of much better multi-AU detection gear on board one can disappear out there pretty easily. As such piracy would depend less upon opportunistic trade lane lurking and more upon intel as to when and where the prey is.
