Pretty sure it was so publishers (printing press owners) could have a guaranteed profit. Those two things (publisher and artist profits) were correlated at the time. Not so much anymore. Streaming/subscription mentality is like planned obsolescence for IP.

This is the most level headed approach to IP I've seen. If you're not willing to use the property you forfeit it. It's a common contact for licensing rights for movies that forces a studio to make a movie or lose rights. That way people can't squat on a licence to prevent others using it.