- Once a copyright expires, the physical medium encoding the work (book, CD, etc...) becomes a commodity, which anyone can replicate. Under good competition, the profit from selling those should be very small. Even moreso in the digital age.

- The article complains a lot that everything is inherited, except IP protection. One can look at it in the opposite direction: these days, many rich people are coming out against inherited wealth. Taxing it to a larger extent than normal would make sense, from a mechanism design point of view. My guess is that this cannot be done effectively; people would just start giving away their property to their children before dying, escaping the "death tax". Copyrights are easier to take away, because they have a natural owner.