That's fine. If the Chinese government wants to commandeer their own citizen's resources to DDoS other people, that's on them. They could very well also direct their state controlled ISPs to do the same. Doing either would be obviously be attributed to them and would be cause for them to be de-peered - solving the problem.

sure. but that would still limit the attack to only come from within CN (and possibly users outside with a CN browser) and not from every potential user who has Safari/Mozilla/Chrome.

It would mitigate attacks from inside China against outside entities, which for somebody not based in China is all I want.

The concern here is people using Chinese websites abroad. The Great Cannon rewrites javascript for a subset of remote users visiting Chinese sites, causing the users' browsers to participate in a DDoS against a target.