I think the reason why other ban crypto because crypto is a new currency, unstable, highly fraudulent and has not reached a certain balance like some other markets such as stock, gold .... Governments have not recognized crypto to protect people against scam risks. Once crypto is more transparent and stable, I think it will be recognized and become more popular.
Government is more afraid that their people could used it for illegal activities like cybercrime which can be hard to track who is the mastermind of it and can many people do such thing because of anonymity of every transactions. However, without banning it can give benefit also to the government because it can help for the growth of economy and no more people can be unemployed themselves.