Bitcoin is not designed for taxes to be paid on it. I beleive the best for government maybe to tax bitcoin users and make it more popular. Just that the charges should be considerate and proportional to the excesses.
Where is you position actually? You said bitcoin isn't designed to pay tax, but the best way is applying tax. Do you agree or disagree about taxing? If it's best way for government to apply tax for bitcoin just to make it popular, bitcoin should be legalized first. When it's legal, it becomes similar to other currency. Then, perhaps people will sell their coins because they get no plus point from bitcoin, it will lead to the end of bitcoin, I guess.
so do you think all the time that bitcoin is an illegal type of currency ? not it is not . bitcoin or cryptocurrency in general is already legal although some countries are restricting the use of it maybe because they have other reasons but not because cryptos are illegal and should be avoided . and speaking of legality , you dont need for a thing to become legal if you really want to pay for tax because even illegal things like drugs are have been already taxed and lastly its all up to you if you will pay tax just to support your country or not .