The ban on cryptocurrencies must be correct. The government is not afraid of cryptocurrencies, but is worried that many people will go bankrupt during the growth period. Only when the cryptocurrency market is re-accepted by the government will they be open. This is to protect the people, knowing that countless scammers want to rely on fraud to get rich overnight, which is much faster than any investor making money.
The government in principle accepts all new technologies with consideration of the added value that exists in these technologies. Why do many countries ban bitcoin, because of anonymous factors and high price fluctuations. The consideration is to protect citizens from losses that might occur if bitcoin is legalized in the country.
Youre somehow right but not totally right because the government you said are not really trying to protect their citizens from losses in terms of investing into bitcoin because almost every investors knew that bitcoin is very volatile but it always for postive side and every losses an investor encounter can still thrive back as profit. However, the government are against bitcoin because of it decentralized in nature and this is why some of them choose ripple, NEO and EOS cause they are all centralized coin.