Because it's already public domain in Britain, and has been since 2000. Since copyright is per-country, that didn't matter for an American case. Past that, Ame

Because it's already public domain in Britain, and has been since 2000. Since copyright is per-country, that didn't matter for an American case. Past that, America is a big enough chunk of the English-speaking audience that its American status is a factor for major commercial projects.