"One reason for her critical neglect is that she didn’t fit in—a reflection of the institutional prejudices of the English literary world. She was a woman writing when writing was a man’s game—not just a man’s game, but a public school/university-educated man’s game." Blithely written about the days when Agatha Christie topped best-seller lists.
I think the writer means literary in the narrower sense of 'literary fiction'. Christie was a genre writer; like F/SF etc. I understand that wasn't quite respectable in the upper echelons of the book world. Certainly the reviewers in places like the TLS would be primarily interested in literary fiction.
The article may seem to take that view, but dispels it at the same time: "a list of 100 or so English woman novelists of the 20th century, a list running from Margaret Atwood to Virginia Woolf." Then it comes up with other possible explanations, all speculative. There's no conclusion.