I agree with you that AI's disruption of attribution is a much bigger problem, but it's also worth recognizing that not everyone has this same motivation. It mostly affects copyleft open source licenses.

Attribution isn't required for permissive many open source licenses. Dependencies with those licenses will oftentimes end up inside closed source software. Even if there isn't FOSS in the closed-source software, basically everyone's threat model includes (or should include) "OpenSSL CVE". On that basis, I doubt Cal is accomplishing as much as they hope to by going closed source.