@dobey I don't agree with " China has an exhaustive set of regulations for smart phone interfaces, that must be met to be sold on devices." China goverment didn't not has such law or regulations of that. Maybe you mean Huawei's regulations.Yes, Huawei don't allow we unlock our phone's bootloader and flash to Ubuntu-touch. Beside, Huawei has its own mobile system according to the news.
But, WeChat,Alipay,some school application,DingDing(a application used for discuss about work),all map apps and so much application only has IOS and Android version. Also all of them don't have a web version.(maybe maps application has one, but it didn't work very well)n They are so important for every day life that nowadays most Chinese people think if a mobile phone can not install thers apps, it is as same as a Nokia 3110. Just like a phone in your hand without Telegram, Twitter,line,facebook.
In my opinion,LACK OF IMPORTANT APPLICATION IS THE BIGGEST PROBLEM TO SPREAD UBUNTU-TOUCH IN CHINA, NOT THESE REGULATIONS.