[leijurv]

I think it has to do with verifiability. https://en.wikipedia.org/wiki/WP:V Essentially everything written has to be verifiable, and if a person doesn't have enough reliable sources talking about them, it isn't really possible to write a verifiable article. See https://en.wikipedia.org/wiki/WP:GNG and https://en.wikipedia.org/wiki/WP:RS