Japanese don't wear masks to protect themselves from viruses. They wear them when they are sick to protect others from their illness.Wearing masks is not an Australian cultural thing. When I was in Japan, it was a common sight.
It seems that this coronavirus went from a bat, to a snake, to humans. The local government in Wuhan covered it up when first detected and now that the central government has found out what's going on, they've gone all in. They did take a beating over their lack of action over SARS. The Wuhan government also shut down internal city transport, but forgot to close the highway out of the city, so a number of people got out before the central government moved in and shut down the highways and airport.
The only BSL4 lab in China is in Wuhan. They didn't use it to study this virus, instead sending samples to the BSL3 lab in Shanghai.
There are reports of 12 other cities in Hubei under some amount of quarantine. If the central government is going all in on this, they might as well just quarantine the entire province.