In that list, he includes Paul Bowles, suggesting that The Sheltering Sky was very, very good, but that his other books were really not up to snuff.
That’s completely bogus and I think the author might even agree had he thought about it more detail. Yes, Bowles wrote only one great novel, but that novel (yes, it’s The Sheltering Sky) wrote several amazing books. This is so because Bowles was one of the preeminent American short story writers of the twentieth century, so his best books were not his novels, but collections like The Delicate Prey and Other Stories or Pages from Cold Point and Other Stories.
This flaw peppers some of his other mentions, particularly F. Scott Fitzgerald whose short stories rival his greatest novels.