That's all because of control. Many governments are agraid and against something they can't control. Same thing here, cryptocurrencies are practically impossible to control.
I agree in you on this.
Bitcoin is being banned because the government is afraid. They cannot control bitcoin as to its price considering that bitcoin really give a good profit. Ofcourse government will want to have some of your profit. I am thankful that my government does not ban bitcoin.
Or they genuinely have no idea how to tackle the issue it as it is a new technology so they decided to ban it altogether until they find a way to properly regulate it. Take china for example, they wanted to trim down scam icos but they have a "positive" stand against cryptos in general.