It just shows the absurdity of copyrighting a tiny segment of the endless road that is the human mind. It all builds on each other, that is all human beings ever do. Drawing a line in the sand is arbitrary and at the end of the day obsolete.
For the one plagiarist who outright copies another one's art and wrongfully claims credit for it a hundred genuine artists and inventors are being stopped in their tracks for evolving what came before them. We are so mixed up that we confuse the two all the time.
Great post!!