> Isn't that the same point piracy advocates have been making for a while?

No. Plenty of people – not just “piracy advocates”, whoever they are – have pointed out that copyright infringement is not theft over the years. Learning, copyright infringement, and theft are three distinct things.

Learning isn’t copyright infringement.

Learning isn’t theft.

Copyright infringement isn’t theft.

These are all different statements, and all are true.

> There is an exposure to (and a gain from) a resource that is traditionally associated with a cost.

“Gaining exposure to” isn’t theft either.

Copyright isn’t some form of “super-ownership” that gives you absolute say over what happens to all copies of the work. It is very specifically a monopoly on the production of new copies, and even that is limited in many important ways and is not absolute.

There is a form of control over information that matches what you want copyright to be though - trade secrets. If you want legal protection that allows you to control knowledge, then it needs to be a trade secret.