It only works because the overwhelming majority of the population and all of the political and economic power lies on the east coast of China in a single time zone. I doubt that the people in Urumqi are happy to have the sun rise at 10 am, and I doubt that anyone cares about their opinions.
I stayed in Urumqi four times (in 1993, 1996, 2006 and 2010), each time for some weeks. It is really confusing that the (traditional) working hours are from 10AM to 2PM and 4PM to 8PM. I found myself everytime looking at the clock substracting two hours. Similar as to when we changed currencies in the Netherlands when the Euro was introduced. I guess it would have taken about half a year stop doing the reverse time calculations.
Given that the sun rose at 10 am approximately 0 times this year [1] I guess the people in Urumql were ecstatic. Also note that the sunrise time varied by about 3h over the course of the year so how many times do you want to change the clocks?
Of course to your actual point and everybody else that brings that same one up. You do not need to wake up at 8am every day ... If the sun actually rises at 1400 then feel free to start your day at 1500. I'm not sure what why people keep arguing as-if they can't figure out a time besides 8am to wake up; look at the world around you, so many people wake up at wildly different times in a timezone.
