That's Christopher Tolkien's opinion of Peter Jackson's movies. I agree more than disagree with him, as I've said here more than once.
The piece in question (from Le Monde) is full of fascinating information about Christopher Tolkien's work and the course of Tolkien-related events after the writer's death. I think it's a bit misleading in describing The Lord of the Rings as "an epiphenomenon" in Tolkien's writing at large. True, the events in that book are only one small piece in a very, very large narrative, but that doesn't mean JRRT thought lightly of it: "It was written in my heart's blood" is a remark from one of his letters (to Christopher, if I remember correctly).
I've wondered how much control the Tolkien family had over the movies. The answer seems to be "not much."
I do know at least one person who knows The Lord of the Rings only through the movies but nevertheless has a pretty good sense of what the story is about, so perhaps it's not all for nothing.