How would that apply in the case of, say, Peter Jackson's 2003, $281 million "The Lord of the Rings" film series?
Does Jackson own the IP? Do actors own part of the IP for every scene they're in? What does Jackson offer to investors, to get the backing he needs to hire loads of horse riders or whatever? Do we do it Star Citizen style, giving Jackson a few hundred million upfront with no obligation to deliver anything?
You make an excellent point. Companies could eg. have 25yrs to make a profit.
On the other hand: if an artist produces something that slumbers in anonymity for decades before it suddenly explodes into popularity and becomes part of the cultural canon, then I'd want the artist to reap whatever benefits possible. That is: if anyone is making big bucks off of that, it first and foremost should be the artist, for as long as they're alive.
On what basis would that form of explosion actually happen? In my understanding of the history of art, what often happens when something "slumbers in anonymity then explodes" it is quite popular in a subculture but then eventually gets mainstreamed when the mainstream culture comes around and people start to explore that subculture. In other words, it is a commercially successful product from day one.