Disney will never let of of its properties become public domain, its got the ear of congress for that.
World A:
Creative works are property just like houses, etc.
In world A, it is supererogatory for Disney to “let” its properties become public domain. Disney can pass it on to his children, down through the centuries, just like a house, etc.
I submit that world A would be a nightmare to live in. You couldn’t write, sing, say, think, make, or do
anything without getting permission from dozens of people who had written, sung, etc. along similar lines.
World B:
Creative works are not property, but are treated as (metaphorically) similar-to-property for a period of time. The length of time is calibrated to that value that most benefits the public. Too short, and art will not be created. Too long, and you veer toward world A
This is the world of the US copyright system – on paper.
World C:
Similar to World B, but the length of time is calibrated to the value that most benefits the content industry.
This is the world of the US copyright system – in practice.
World D:
Creative works are never treated as property: they enter the public domain immediately.
World D is the context in which most of human history occurred.
I think a case can be made for worlds B and D