I think this fascinates people in part because we sort of think it can't happen anymore. With 7 billion people, GPS, satellites, airplanes, cell phones, we think you can't get lost like this, you can't be so extremely alone. We think space is the only frontier left.
It flies in the face of our mental models of our world. On top of that, it is an extraordinary personal experience that is fascinating for that aspect. So many of us struggle hugely to cope even with the support of modern civilized life. I can't imagine figuring out the logistics of coping practically with such a situation. Coping psychologically is even more unimaginable to me.