They might not be pirates.
But we in Maroccidens damn well view them as pirates. They used to hire out droves of assassins and send'em against us. They rampantly loot lands. They sail in ships with red sails (or so the RPs went). They are ruthlessly individualistic and greedy for gold. Whether it's a pirate-themed realm or not, we in Terran will continue calling them Pirates until they clean up their act, get a reasonable, civilized government, learn to play nice with the neighbors, and apologize for all that nastiness from earlier in their time.