That sounds great in theory. But you're punishing specific people for the actions of a third party.
I believe the argument is about the morality and reasonability of how copyright is implemented, especially when it comes to academic publishing. Authors make almost no money on their publications, which is as it should be, since they are usually payed good salaries while they write. I have published a chapter of a book with a well esteemed publisher, and although the book presumably sells well, I have not seen one penny. Which is as it should be. The publishers, however, make insane profits because most academic libraries need to buy an overpriced copy of almost all published books, and students must buy overpriced text books.
In recent years many governments, including the US, have started a process where they demand that all research that they pay for should be published openly. The problem with this, of course, is that publishers actually contribute something of value, which is quality control an editing. The solution is to find better systems for taking care of these tasks than having publishers who exploit both their authors, the universities and the general public. The biggest losers in the current system are academics in the 3rd world, since their universities often cannot afford to give them access to published research, not even their own. Z-Library is just taking a shortcut to rectify a huge problem that the governments in the world are already in the process of fixing, just more slowly.
So, there is no third party being punished in this case. That would have been the authors, but in most cases they don't get much payment for the sale of books or articles anyway. They get payed for doing the research. There is one abusive party, the publishers, and then there are victims. The governments are victims, although they to some degree protect the publishers who make them pay for the same research twice. The authors are victims, since access to their research is restricted. And the general public are victims, since they have no access to the information they have payed for through their taxes.