Copyright in the US started out lasting for a year, to "give the creator a chance to earn an income from their work". If you're a songwriter, for example, you would be expected to write more songs to earn your living. The trouble came when publishers, record companies, etc started buying all the rights for stuff when they put it out, and then needed to protect their corporate income so they lobbied for changes to copyright. In the modern world (say, the last 80 years) the largest percentage of copyright monies do NOT go to the writer, but to the publishers, labels, and other rights owners behind them. You can find many articles online from successful song writers and musicians showing how they made very few dollars off the sales of their giant, million selling hit records.
Tim in Bovey
2 Names come to mind: John Fogerty and Frank Zappa.