I have to say this explanation is plainly wrong and ironically for a piece about discovering ones Chinese identity reads as an extremely American view the Chinese economy.
The Chinese economy is not growing at a 'blistering pace' because of the long hours worked by these people. If this were true, we would see it in productivity figures but China is actually very low on those measures. It also seems to imply that the rest of the world is just lazier than China hence the lower growth. Are the people of South Korea for example that much lazier than their Chinese counterparts?
China grows at a rate of 6% because GDP growth isn't a measure of output in China in the same way as in the UK for example, it's a policy decision. This doesn't mean they invent the figures which many people seem to believe, the activity is actually taking place and that's obvious if you've ever been to China.
The economy is structured in a way to achieve growth targets. Local and provincial officials are rewarded for achieving growth targets with career advancement, so they come up with creative ways to fund dubious infrastructure investments or just use proceeds from land sales. SOEs engage in investment and production that would not be economic if not for discounted interest rates given by state owned banks, funded in part by negative real rates for deposit holders (the people working 16 hour days). These banks have loan books elevated levels of non-performing loans, but because of the closed financial system they don't have to realise these losses and can be quietly recapitalised if necessary. High level party officials have been talking about rebalancing from export and investment to consumption led growth since Wen Jiabao in 2007. Since then consumption share of GDP actually fell even lower.
China is not some ticking time bomb ready to explode on debt, they have similar levels of total debt to GDP as the US and EU do. But equally it's not some hyper efficient utopia full of the hardest working people on earth.
This line of thinking is really bothersome because believing that 'China is outworking us' will invariably result in political rhetoric in western countries aimed at making workers work longer hours or peeling back various labour protections. Not to say no reform in these areas is necessary of course.