Does art grow better the more it imitates nature? My notion is that it grows better the more it improves or alters nature through an passage through what we might call the artist's soul, or vision. Countless artists have drawn countless nudes. They are all working from nature. Some of there paintings are masterpieces, most are very bad indeed. How do we tell the difference? We know. It is a matter, yes, of taste.
This is the kind of thing on which intelligent people can disagree. Surely another definition of art is simply whether or not a particular entertainment is meaningful to its audience. Whether or not they recognize their own aesthetic philosophy within the work must also be relevant.
That said, Roger is completely right about this, and those who are reacting against him are completely wrong.