Do you think bitcoin can ruin a country?
I dont think so. It depends on how people use it. If people will use it in illegal actions it will surely destroy a country.
The problem is, how do you know it is being used for the right reasons? The government regulatory authority keeps an eye on all transactions to make sure nothing illegal happens. Tax is the backbone of any economy. With bit-coins no one knows whats happening with the wealth, what is being sold and purchased. In a world where everyone is looking to evade taxes, it is such an easy currency to save yourself from taxes.
How can we also know that the tax we are paying goes to the right place? Yes the government will not stop to investigate so they can control bitcoin which is not gonna happen. Hey! this is a great technology then why keep on banning, government can regulate this but its not a good thing to ban bitcoin. We need this thing and we should support bitcoin so we can have a great future ahead.
I agree with your opinion with the government to legalize bitcoin as digital money which is used as an investment why not because bitcoin is very promising to invest.