They Still Don't Get It
While it is true that OW does not make registration with the private registries mandatory, registration will be required if photographers want the same protection for their works as they have now. Specifically, for those photographers who register their photos with the Copyright Office, they also would have to register with the private registeries to rebuff a potential OW defense and thus be eligible for statutory damages, the primary weapon that creatives have to fight infringements.
Currently, copyright infringement is a commonplace occurrence, even by major corporations that should know better. But perhaps the infringers do know better and are taking a calculated risk that the infringements won't be found, even with the possibility of having to pay statutory damages. Most of the excuses are laughable, but the infringers still don't want to pay for their "mistakes." OW will provide them another excuse - "we conducted a 'diligent search' for the copyright owner but could not find him." That's because the copyright owner took the advice of PK or ALB and didn't register with the private registries, because it wasn't required.
Even now, if a photographer does everything possible to protect her work - registers her photo with US Copyright Office, puts a watermark of her copyright notice on the photo and embeds meta data in the photo file with her contact info, disables right click on her website - her work is often infringed. All of these protections are easily overridden (an infringer can strip the metadata, clone out or crop the watermark, override the right-click disable). The photo that has been stripped of these protections can be distributed throughout the world in seconds, thus leading to "innocent" infringements. The potential to be awarded statutory damages is the last defense against unauthorized use. But the OW Act takes away the statutory damages option unless the photographer registers the work with the private registry/registries, as well. Moreover, there is no guarantee that the photo will be found on the registries because the current technology is not foolproof. Finally, registration with the private registries likely won't be free. Perhaps the proponents of OW will pay?
In sum, the current OW bills weaken the rights of creatives. So who really is under a misconception?