It’s a historical fact that Pirates don’t have a lot to say. They communicate mostly with scowls and grunts. When they do have to say something while sailing the high seas, plundering booty and hunting for treasures, it’s usually just “Arrrrr”.
So a Pirate’s keyboard keeps things simple with just the basic essential pirate keys. Arrrrrr. Avast. Even this keyboard, simple as it is, is hard to operate with a hook hand.