It's China: their societal engineering is pretty much authoritarian and somewhat draconian.

I wouldn't be too shocked if, sometime in the future, they recorded every turd a citizen passes, and instituted some type of mandatory fibre-per-day count for their citizens.

Crypto, by its nature, undermines their near-paranoid control of their citizens' lives and finances. That's why they want the exchanges shut, while also looking at the technology behind bitcoin and other crypto-currencies for their own uses.

Nothing new there: there was news a few weeks back that Russia, while not shutting exchanges, was looking at the block-chain technology for its own economy.

It's true what they say: China is shit at innovation, but once they understand something developed by others, they can mass-produce/replicate it on a grand-scale (even if half the time their exported products are shoddily-made, heh).