Negativity aside, this looks like the future I hope that consumer grade cars/transportation will eventually have this. I can imagine a highway of the future with a lane for autonomous vehicles instead of truck drivers.
Heck most airplanes fly themselves.
The unmanned option is better in case of piracy, since due to lack of hostages there is less pressure for ransom and it's safer to re-capture the ship before it can be delivered to a pirate friendly port.
The real vulnerability of unmanned ship is against small-scale theft (a rubber dinghy boarding, opening a container and stealing a few TVs), but for large cargo ships thieves can do the same without the crew noticing; so it can be covered by insurance probably.
I believe the pirates are in it for the insurance money for the hostages anyway I doubt they want to fence any actual goods.