Makes total sense. But it comes from the fact that we are accustomed to the thinking of keeping different records for various types of things in everyday life.
If a consitnt fingerprinting protocl could be devised, a single blockhain can record every sort of ownership. Also, with multiple blockchains available, the consumer will have to know which blockchain to query.
Any company who pursues this idea must figure a standarised protocol of fingerprinting anything to become a monopoly. My thoughts.