I do think that people are looking at what China has achieved for one region, and viewing it as achievable for the whole of the UK. Even excluding cultural differences, China were/are able to sustain their lockdown because other parts of the country are still running and they are able to bring in medics from other areas.
I think some of the government strategies are wrong- and I think travel decisions may be influenced by EU negotiations and other factors as well as what's best for health, and this is totally wrong.
However, they have said they would consider regional/individual city lockdowns. I think we have to acknowledge the extreme difficulty (impossibility?) of locking down the whole country!