It might be that in order to have a coherent discussion about this we need to separate the concept of copyright into two areas. One is the right to exclusive d

It might be that in order to have a coherent discussion about this we need to separate the concept of copyright into two areas. One is the right to exclusive distribution of the original work. The other is the right to make derivative works from that work. In both cases the commercial/non-commercial distinction may also make sense, but I think these are the gross categories. Let's call these two new rights "cloneright" and "adaptright" Since we lump them together, these two things get mixed up. Cloneright addresses concerns about the ongoing availability of a work (or translating the work to a different format) causing problems -- old video games, old films, old music, out-of-print books, things like that being lost or hard to obtain because making electronic versions of them is not possible without the approval of the copyright holder. It seems reasonable that this should lapse on a relatively short time horizon. Adaptright is a different matter, and is harder to quantify. I don't think it would be acceptable for other authors to write sequels to an author's books, or studios to adapt them without the original author's permission, for a longer timeframe than cloneright makes sense for. Saying that the lifetime of the adaptright is tied to the author's lifetime makes sense here. It can take a long time for a book to be adapted into a movie, and it makes sense to have the original author to have some say in that (unless they choose to forfeit that right). It might make sense to break this further down by commercial/non-commercial usage, or even by type of copyrighted work (relatively few songs, for example, are successfully adapted to movies or books, so adaptright might have to mean something else there) but I think this is a better framing of the copyright discussion than lumping the two gross categories together.