Did you RTFA? It's like 20 lines of text, that's exactly what it explains. Any entity with the ability to print money can simply buy a dominating share of the hash power and force all the honest miners to either sell out to them or go out of business.

the network is only global and decentralized to the extent that the miners operate with a profit motive. The government that prints the world's reserve currency can afford to print more money than honest miners can afford to lose. Game over.