Tax law is dependent on your country and locality. Recently in the United States, the IRS has declared that Bitcoin is to be treated as property, not currency, for tax purposes. All income in the US is taxed, regardless of what form it takes. If youre paid in bitcoins, youre supposed to pay taxes on your earnings at the BTC/USD exchange rate when you receive payment.
Is it a good decision or bad?
I think if bitcoin legalized in a country the government will apply taxes in every transaction we will make. Taxes is very important to the economy of a country. why? because it can be a fund to the government to used in building a hospitals, schools, education assistants and so on. Our taxes is distributed in may sectors of the government down to its area. Many people will rely in bitcoin and its good source to the government to collect it. And I think they will keep to control the crypto price after they legalized to provide a regulation for it to follow so that they can implement it well.
As we know, Bitcoin is popular in the crypto market and it can be a advantage in the government because some people are engaging bitcoin that is why they will got interested to it.