I think the key concept is that a hit song/film/book owes as much of its success to its audience as to its creator. Returning super succesful properties to the public domain faster reflects this.

A similar argument could be made for open source software, you don't want anyone to have full control over any key element of the software ecosystem, because at a certain point theyre just milking the venefits delicered by the wider ecosystem.

Corporations may be the same.