It's not just assumed, it's celebrated when a work of art gathers fans who produce their own, inspired content.
Not sure why it needs to be over-complicated or different for silicone neural nets. But I think it will get very over-complicated, if not politicised, in the following years.
It is implied that if you are using the work by youself, or via a tool you made youself, it's fine.
However works that you redistribute, by copying it yourself or indirectly by tools, said silicone neural nets being one example, instead require a "wide redistribution license agreement", and those are implicitly limited by default unless the work is put in a sorta public domain license.
You are absolutely buying a license to read the material when you purchase a book. That's why books cost more than the paper they're printed on and why pirated books are illegal. The "distribution" rights you refer to stem from the "first sale" doctrine[0], which acknowledges that the first sale (e.g., you buying a new copy of a book) of a physical object embodying a copyrighted work grants limited distribution rights.
When you buy a book, you’re not paying a licensing fee. You’re exchanging for goods. You’re granted very few rights to own a copy of the work. But they’re almost all to do with distribution. None of those rights is the right to read it.
>You publish in public, you automatically grate licenses for the public to consume and transform it.
By this interpretation, all the artists upset by stable diffusion have given tacit permission for their works to be used as they are published in the public. Even though those works are posted to websites, the artist has not granted any rights to the viewer of the work.
> only natural humans have that ability according to the law
The law is not explicit about this, and we have case law that describes non-human entities as having rights associated historically with personhood. This is definitely not clear, nor is it obvious.