The distinction between author and their estates is fascinating: the stereotype is estates mismanaging the art, but that usually happens because the estates want to be “artistic” themselves.

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).

Imagine what a better world we would live in if the Tolkien estate was able to kill D&D in the cradle as they would have liked...

/s

> The inheritors are in a better position to kill the author-- or just allow them to die from neglect-- and are incentivized to do so by postmortem profits.

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.

> The inheritors are in a better position to kill the author-- or just allow them to die from neglect-- and are incentivized to do so by postmortem profits.

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.