John Wyndham — the author of Day of the Triffids amongst others — died in 1969.
Ten years after his death his estate allowed the novella Web to be published for the first time along with a couple of other books not released during his lifetime.
Why wasn't the book published during his lifetime? Or if this was the last title he wrote, why the 10-year delay?
The book doesn't seem to be incomplete and —although a little short— after reading I didn't see a reason why it wouldn't have been released. Bearing in mind the great success that several other of his novels had I'm sure a publisher would have known that any release from him would have sparked interest and profit.
To a reader in 2014, the story is a little clichéd but I don't know if that would have been the case when written and I don’t know when he actually wrote the story. Besides, a few clichés doesn't get in the way of a riveting read.