So by same token you would say people don't have two eyes but in practice they mostly do. How is that more useful of a sentence than saying "People have two ey

So by same token you would say people don't have two eyes but in practice they mostly do. How is that more useful of a sentence than saying "People have two eyes, except in rare circumstances". It's obvious from article language is causing problems for the author. And by optimizing for the edge case, you impose problems for the most common case.