At one point in time I was an English major. As an English major I had to read a lot of Great Literature. Middlemarch, Bleak House, Pale Fire, etc.
Since graduating and entering a different field I have mostly read books for entertainment. Fantasy and science fiction novels like A Song of Ice and Fire, The First Law Trilogy, The Magicians, etc. Books that are competently written but are not usually thought of as "art" or "literature".
Academia has grown warmer towards these popular works over time. Courses are now taught on Harry Potter. But some of that originates from English departments trying to attract students and remain relevant in a market-driven world. Most academics still look sideways at genre fiction, especially if they were trained on older forms of literary criticism.
This is where Gene Wolfe comes in. He's one of those writers who has attracted enough critical praise from the Right People to be looked at in a slightly more favorable light. He was written up in the New Yorker as "Sci-Fi's Difficult Genius." There are multiple books analyzing his oeuvre, such as Attending Daedalus and Solar Labyrinth. The quantity of allusions in his books and the inserted stories as well as the unreliable narrators send readers scurrying to reread each text multiple times to piece together clues from the dense prose. Reading his work made me feel like an English major again.
But he's still not without his critics. Gene Wolfe was put forward as an example to reticent academics that genre fiction isn't just shallow entertainment. Unfortunately they still found plenty to criticize, including the first image in Book of the New Sun:
"The locked and rusted gate that stood before us, with wisps of river fog threading its spikes like the mountain paths, remains in my mind now as the symbol of my exile."
The criticism is that the image does not evoke the feelings Severian, the narrator, claims to associate with it. Fog as mountain passes does not evoke a sense of alienation, impenetrability, or separation. It creates a nice visual, but it doesn't achieve what a truly great writer would consider fundamental to an image that the narrator specifically says is a symbol.
This was something I hadn't considered, that successful imagery should not only use the right words to evoke an image in the reader's minds, but should also be psychologically true to how the character perceives that object. The fact that Gene Wolfe apparently fails at this in the second sentence of his tetralogy makes it hard for these academic critics to find his work worthy of serious discussion.
So for now I guess fantasy and science fiction will remain as mere entertainment, appearing at Universities in bit parts in 100-level classes to rope in students. Until genre gets its Nabakov or Melville it will have to endure plenty of side-eyes from those who study serious literature. Hopefully an author of that caliber takes up the challenge.