It doesnt because it is completely bogus to conflate scientific inquiry, research and invention with the creation of art, music and literature.
I'm sorry?
That particular section of the Constitution was meant to refer to both copy rights and patents.
There is a legitimate public interest to be served by a copy right of limited times. However, after such time has passed (originally 28 years, which is a hell of a lot more reasonable than eternity), the work was supposed to enter into the public domain.
You still didn't answer the question of whether we should be paying the decendants of William Shakespere if we want to own a copy of Hamlet.
Further, should Disney, have had to pay Rudyar Kipling's decendants for the right to make a cartoon of "Jungle Book" back in 1968, which was the year after the copyright on that book expired? If the copyright terms existed back then that do today, they'd not been able to make that cartoon for another ten years from today without paying royalties. You'll note that Disney is all for the public domain when it benefits them, but don't even suggest that "Steamboat Willie" should ever be allowed to enter the public domain.