Agree. Skillset and response will determine the success. Japan govt has a good precedence of centralized security scanning for country’s Internet, so hopefully it is a positive.
Vast majority of Internet users are not security savvy. Doing a baseline scan with appropriate remediation guidance will go a long way.
It depends on what kind of actions they wish to do with the resulting scan/hack.
If they offer services to secure people/companies free or cheaply, then its a overall large positive.
If they give it to their equivalent NSA apparatus, that's a major bad.