I have long complained about the orphan works problem and the need to free them up through copyright reform. This case is a quintessential example and copyright reformers should take note.
Copyright needs some kind of usucaption mechanism: if the holder doesn't make any effort in maintaining his works available for an extended period of time they should automatically enter public domain.
And that (c) applies to only the published copy. It is very common, even standard in many fields, for researchers to make the same material, just not exactly the published copy, publicly available. See eg arxiv.org.
