I've been told that this is the primary purpose of the whole thing. It's a back door protectionist tax on foreign Internet services done in such a way as to not trigger taxation provisions in trade deals.
Someone who once specialized in breaking the GFW for NGOs and activist groups, and who worked a lot in China.
Censorship is still a motive, just not the only one and maybe not even the primary one. The GFW is just too porous to be an effective censor, but it does prevent foreign Internet based SaaS from competing in China. It means to compete in China you must be in China where your IP can be easily appropriated since the Chinese state must also have root on your box (or the cloud host).
