While not all societies are democratic, they do all have politics. And it's not always safe to annoy the local political leadership.  Or financial leadership.  Or someone with a bigger family than yours.  Steal something, seduce someone, insult someone, offend someone, or just screw up someone's plans, and someone and their friends may start looking to get rid of you permanently.

If you are politically astute, it may be possible to read the situation early enough that you can leave on your own terms, and take a chance on the water, rather than staying and waiting for the axe to fall.  

(Heck, steal the big guy's boat on the way out.  Not like you're coming back, either way.)

Iceland was settled in large part by political exiles seeking to escape the consolidation of power by Harald Fairhair.

40 years ago, several Americans sought political refuge in Canada.  

The US continues to rehome refugees.  Some of them intend to stay; some of them consider themselves exiles and intend to return "when things get better."

None of these people were subject to to a formal judicial process, for example, the Athenian  procedure (ostracism) where they kick someone out for 10 years.  

 

Even if there is, the fact that it is circular, and where it leads to, after it hits the coast is not necessarily apparent to the locals.  

("If you sail to far north/south of home, you may be caught in the big current that goes east.  Nobody knows where it goes; nobody has ever returned.")

The locals may know it goes north, but are possibly not interested in going far, because it goes north *and does not come back*....