There is no monopoly on vision, and frankly, the question of the ownership of media and culture, interoperation, access to historical documents etc. has been evident to a large number of people for much longer than you give credit for.
When a paper book went out of copyright, you had the book, and that's all you needed. "The source" might have included a bunch of notes and earlier drafts, but broadly the value was in the finished article.
Software itself is much easier to reason about. The GPL really embodies an equivalence relationship between the "source code" and "object code" of software products. Practically speaking, software was the only area in which this could possibly have made any sense before commodity computer hardware, and digitisation of content production workflow.
So although a recording engineer's "patch sheet" might have shown which way the compressor was set for a specific hit single, or their studio notes might have recorded which note a guitar actually hit and via which microphone, it wasn't digital, it wasn't recorded, it was never considered part of the "product" that was the song, and it isn't so obviously part of "the source" to anything.
Now however there is increasingly little difference between media and software. The DAW files or stems used to construct a hit single, the LaTex used to produce a book, the Java used to write a DVD menu, C file used to compile a library.
For example, to qualify for copyright protection at all, should an organization or individual be required to make available in escrow, the inputs "as customarily used" [e.g. script + equipment list + shooting instructions + concept art for a movie but not costumes, unencrypted searchable rich text and vector graphics files for a book, complete source for a website]? Should a patent grant be allowed to proceed if and only if there are reasonable means by which the patent would be usable by the public after its expiration?
To me, the "real problem" is a determination on where on the line from closed-to-open we as a society should be, and it can't be solved via licenses.