There are many who believe in art for art's sake, who believe particularly that art can have no utilitarian value, and furthermore would be offended by the very notion that art could be utilitarian, as if such effort would be propaganda that tarnishes and blasphemes the holiness that is artistic endeavor.
I am not one of those people.
To believe art can have no utilitarian value is to believe that the way people think has no impact on the way they act or on the shape the world takes. And if you believe that, why would you read for anything other than entertainment value? To ignore art's utilitarian value is to demean art itself, to make it no more useful than cheap entertainments like soap operas, spy novels, and formulaic sitcoms.
But art can do more than entertain. Art can change the way we think. And the way we think affects how we act and how we shape the world (as individuals and as groups). Art for art's sake is its own form of ethical value, of course (within Aestheticism, a writer concerned with morality would be the "unethical" artist, the sellout, creating debased literature). And you can include me among those who would elevate the importance of art in the overall scheme of human existence and achievement. But that is partly because I recognize ways in which art alters our worldviews, our self-perceptions, our consciousnesses, our behaviors. Perhaps art can't be narrowly utilitarian; perhaps it is impossible to predict the actual "use' to which art will be brought. But that doesn't mean that it exists for itself; it is not only writers who should read.
Finally, the most important point.
In fact, Aestheticism is itself narrowly utilitarian. If art exists for art's sake, then the artist examines another work of art only to determine ways he can "use" that art in his own art. If art has no value outside itself, the only art meaningful is that which is useful to the artist, and to that artist all art will be viewed in a utilitarian manner. The artist will say, "How can I use this to shape my own art?" THAT is a debased utilitarianism. The "Aestheticist" artist CAN ONLY EXAMINE ART IN TERMS OF ITS UTILITY TO HIMSELF.