Because chiph is offering a fictional explanation for a real world phenomenon. There have been lots of scientific studies involving randomness in fields as diverse as economics, game theory, gambling behavior, and parapsychology; if 'luckiness' was a measurable characteristic of people then you'd expect it to reliably show up in such contexts. Invoking it as an explanation where a simpler alternative exists (the idea that some people are more skilled at analyzing current affairs) is illogical.