It may be true if you're on a lake or in a bay, know the area well, and your intention is to just go and flex your sailing muscles. To practice, enjoy, check out something you're aware of but haven't actually navigated, or something else that's similarly within easy reach.
It loses its applicability when you consider that, no, some sailors actually do have destinations. And some trips are long or difficult enough that they do in fact require planning, specific goals, timelines, and all manner of other preparation.
I'm sure it's not a perfect metaphor, but the point is that the artificial limitation of "hackers hack to hack" is short-sighted and fundamentally flawed. Some do, some don't, and I would say most are somewhere in between. But please don't make the mistake -- on behalf of others -- of defining the entire community in terms of your preconceptions about what hackers do or don't value or attempt in an absolute sense.