I actually have a similar essay in the works of my own, as to why some not-great novels make better movies, and why the obverse is true as well.
I think some of this certainly applies to TV, too, and not just because TV’s better suited to catching all the nuances of a long-form work of fiction. There are some things in a good book that you simply can’t film, because they are a product of being written and are a product of the interaction between the written word and the reader. TV (and film) are wholly literal, and so anything you film takes on far greater weight than what is only hinted at on the page.