Then the publisher loses out on exclusive publishing rights and also loses money. It's in their interests to keep it in print so long as it's a profitable book, even if they have to pay some percentage to the author. Once it goes into public domain every publisher can reprint it and the original publisher has to compete with them on price.
Part of the problem here is a change in tax law a couple of decades back where the backlist as a bunch of printed books in a warehouse became a tax liability when Congress tried to close a tax loophole which non-publishers were exploiting.
Rather than the old model of printing a reasonable print run, selling books as demand allowed, and keeping unsold books in warehouses only paying tax as they were sold, the new laws required paying tax on inventory each year --- so any books not sold in the first year were not as profitable, hence book remaindering, and the current mess.
I'm not arguing for it (or against it for that matter), I was just pointing out that the analysis in the comment I responded to didn't make sense. Every book won't be allowed to fall out of print and copyright just to exploit the authors because it would also hurt the publishers, they also benefit from exclusive publishing rights. Publishing rights are granted by the copyright holder (the author) to the publisher, much like patent licenses.
Regarding unprofitable books, they'll fall out of print anyways because they're unprofitable. Those authors won't be getting ripped off because they won't be making money either way beyond initial commissions and what few sales they get.
> Much better for it to revert to the author in that situation IMO.
The publisher doesn't hold the copyright, the author does, so copyright (the particular right under discussion) can't revert to the author as it never left the author. What the publisher holds is publishing rights per a contract with the author. That could revert back to the author (or be voided or however it's structured), and that would be reasonable but we don't need any laws for it, that would fall under normal contract terms. Whether it's a common thing now or feasible for a particular author (with no clout? maybe not, with billions in sales from prior books? probably) is another matter.
