For me, a good book is one that I will read and re-read. On each reading, I get to know and understand the characters or their situations better. That is not the case with this book.
And yet.. the story is well-written, and Barbara Pym is always worth reading. Perhaps the characters are just not real or believable. The anthropologists come and go, and there is little in their personalities to engage the reader or to distinguish them. Tom and Digby, the students, are mere devices to move the story on. Deirdre's love affair is flat and Tom, the male lead, is one-dimensional.
Comparisons with Jane Austen are somewhat tenuous. Pym is following the fortunes of a group of anthropologists and the relationships between them, but the characters are, on the whole, lifeless. With the possible exception of the bossy, middle-aged spinsters, there is no-one in this book that a reader could be passionate about.