Any benefit from the work being public domain is diffuse, it won't create a windfall for any particular party. The residuals on the other hand are quite concrete, particularly when an author's preferences are capping the market for their work or when the publicity of their death will create newfound popularity.
An estate tax of 100% would eliminate this moral hazard; but the estate tax is already unpopular when its exemption amount means that few estates pay any tax.
> Any benefit from the work being public domain is diffuse, it won't create a windfall for any particular party.
A defendant in a copyright infringement case would have a windfall if the copyright was extinguished as a result of an untimely death.
Most artists are terrible at business. They do dumb things for no reason.
JRR Tolkein and his estate is prime example. JRR signed away all movie rights for a nominal sum. His estate fought tooth and nail for their rights, while still allowing grey zone stuff to develop (Dungeons and Dragons).
/s
This is true now, with or without copyright reform. If the author fears, they can make a will or trust, just like it is today. Not sure why this consideration would factor as a negative signal.