The Hobbit from TOEIC 900?

One of the greatest philologists of the last century was J.R.R. Tolkien (Cf. Tolkien as a Philologist).

One may associate his novel The Hobbit with a genre of children's literature. Tolkien actually intended it for kids, but one may wonder why the book (below) has a cover saying it is for the English learner whose TOEIC score is above 900.

It's not a book for children at all, nor a simple, plain tale of fantasy.

Of course, the TOEIC score is just one measure by which to assess one's English skill, but 900 is very high, far from being an easy reading material. The score might be indicative of Tolkien's creation of highly complicated as well as sophisticated world.