I agree that it felt as if it came from nowhere, but it was still interesting.
I wonder if the interviewer raised the issue because the "Artemus Foul" series is a children's series - though not a picture book - and because Doctor Who, for many, is considered a "children's" series (rather than a "family" series).
But in any case, what those have to do with picture-books... but it was still an interesting point.