Many have said that the .6 number only holds as long as your healthcare system holds up
I think Whuhan is a good warning of that. Before the social media lock-down, there were stories of entire wards of people with pneumonia just being moved out of the hospital to unknown destinations because there was no room in ICU and no available ventilators. I suspect the true extent of what happened in Wuhan won't be known for years. Hospitals in SK are struggling with the numbers they have, and even though they only list 52 as "serious", there are many thousands hospitalized.
One of the problems with evaluating the seriousness of this virus is the complete lack of consistency in counting, describing, identifying and treating patients. You just can't compare one countries reporting to another as there are no standards.