The book sells a million copies and the publisher refuses to pay the widow and child anything because the work is now in the public domain. Justice has been done?
I think a simple period of time, like 7 or 14 years, or even 50, makes more sense.
In regards to your example, the publisher has a contractual obligation with the author, which is obviously part of the estate.
My argument is that even if the author has a deal with a publisher for a particular book, that should not prevent others from being able to create new books, movies, games, etc based on that book.
As a counter example, imagine a 25 year old, with a wife, who would have been able to create the best game ever in 2010. Unfortunately he dies in 2015.
The game would have sold millions of copies if it was published, but unfortunately the character of Mickey Mouse is integral to it, so because of copyright the game cannot be made until 2024 - 58 years after Walt Disney's death and 96 years after the first appearance of the character.
What you are saying is that all of the benefit goes to the publishing company, not the public. Not really.
The reality of normal people is that a big part of the reason they work is in order to provide for the people they love. This is why copyright exists in the first place—to protect the motivation to produce creative work, knowing that the benefit won’t be stolen from you. Knowing that if you die, the benefit to your children is immediately forfeit actually reduces the willingness for people who aren’t misanthropes to take on that risk.
Most pension systems only allow minimal contributions to third party's about £3.6k in the UK and the USA's 401 system is to be blunt a bit crap.