One downside of any sort of copyright registration requirement (probably especially one requiring ongoing renewals) is that it benefits corporations at the expense of individual creatives. Disney's lawyers are not going to forget to renew and the revenues involved mean that any registration is likely trivial. Not so for an individual author or photographer.

In fact, groups representing authors and photographers have opposed orphan works legislation in the past.

The US used to require affirmative action to gain copyright protection but this was phased out to be consistent with most other countries.