The US Government - the de facto licensing wing for the Western World - enables it as it positively impacts the US balance of trade in the exploitation of copyrighted works.

So long as lobbying by the Disney Corporation and others is allowed, the concept of the Public Domain is vilified to the point of felony; whereas the likes of Eldred v Ashcroft call it out for what it is - corporate welfare at the expense of public utility.

https://en.wikipedia.org/wiki/Eldred_v._Ashcroft