copyright only goes one way

My father (who's an author) and I have a disagreement over copyright; as I understand his view, he thinks that intellectual property should be sacrosanct forever, or at least for the entire life of the original author (he points to Edna Ferber, original author of Show Boat, who apparently did not get royalties, although I can't find a citation of the copyright story now). However, with more and more intellectual property being created and owned by corporations, there is no original author who can die... so the property never comes into the public domain.

The graphic below, from The Optimist, speaks my mind, more or less:

It's because of this that I'm undecided about intellectual piracy.