Not so notable is the rough dividing line between public figures and those who are not. George W. Bush is a public figure as as most of those who regularly appear in the media. Those whose doings are not ordinarily covered by the media are not public figures, although something interesting may have happened to them and there has been spot coverage.
In your own words, that's a "rough" definition. We need a precise and objective one, otherwise this proposal will just result in more arguments.