As the article demonstrates, when the quality is extremely low, the consumers suffer. Also, in this case, the price of the pirated books is the same as the price of the authentic books, so this is not a good demonstration of Karsten’s armchair economic theory of software piracy. In this case, the consumer loses and the real authors & publishers lose, while these fraudulent middle-men, the fake publishers and Amazon, pocket the difference in price. This is bad for the consumer and bad for the economy, in addition to being illegal.
Your question implicitly is asking why we even have Copyright Law and/or the Berne Convention, which is something that has a long a rich history. I don’t feel like we need to justify the existence of copy rights. There’s a rich debate on how long copyright should last and what the limits should be, but very few people suggesting we should just get rid of it completely and allow the pirates to flourish.