The author dwells on the possibility of the worst case scenario, naming the main potential reasons:
– Fraud (the possible Bitfinex/Tether collapse)
– Blocking off of fiat/crypto gateways that could cut Bitcoin and other cryptocurrencies from the “real” world.
– China nationalizes their all mining operations one way or the other (an idea from comments).
The write-up suggests possible solutions for all these scenarios, so reading the article is really worth it.