I think the most common aspect why other countries keep banning cryptocurrency is due to the security measures. Many already become a victim of scams at many still doubting if there is someone who is manipulating the prices of cryptocurrency.
I think After crypto is more transparent and stable, I think it will be recognized and become more popular. I think the reason why the other ban is crypto because crypto is a new currency, is unstable, is very fraudulent and has not reached a certain balance like some other markets such as stocks, gold. The government has not recognized the crypto to protect people from the risk of a scam.
For me,some countries have banned bitcoin because of the fact that it is not legalized by the government itself.Because of its high volatility,the price varies from time to time making most of the people become confused since they are used with fiat currencies with fixed amount.