Works moved out of the public domain?

Seriously?

The Supreme Court on Wednesday upheld a federal law that restored copyright protection to works that had entered the public domain. By a 6-to-2 vote, the justices rejected arguments based on the First Amendment and the Constitution’s copyright clause, saying that the public domain was not “a category of constitutional significance” and that copyright protections might be expanded even if they did not create incentives for new works to be created. The case, Golan v. Holder, No. 10-545, considered a 1994 law enacted to carry out an international convention. The law applied mainly to works first published abroad from 1923 to 1989 that had earlier not been eligible for copyright protection under American law, including films by Alfred Hitchcock, books by C. S. Lewis and Virginia Woolf, symphonies by Prokofiev and Stravinsky and paintings by Picasso.

 How exactly does this act to promote the creation of new works?  Any possible incentive to the creaters is long past.  Notice that this period ends in 1989 -- how many people would have created more works jsut in case they could get copyright protective in a foreign market 23 years later? 

I am not against intellectual property rights (rather the converse) but I question is need for such long term protection for pieces that are decades old.  At some point the public domain is the right place for these older works, as it gives them a chance to be rediscovered by people looking for inexpensive content.  That is probably a better legacy for the creators than any minimal stream of royalties could be at this late date.