The Copyright Office didn't construct an exemption out of whole cloth - they cannot do that, and they'd be overruled by Congress if they did. It's a recognition

The Copyright Office didn't construct an exemption out of whole cloth - they cannot do that, and they'd be overruled by Congress if they did. It's a recognition of the underlying fact that the DMCA does not cover TPMs that do not control access to a copyrighted work. The actual text of the law says that.