I think it won't happen as long as bitcoin user keep use legal services and government ask every legal services which accept bitcoin to include tax as well which automatically converted to their fiat currency.
The real problem when bitcoin user spend their bitcoin which don't take taxes at all such as non-registered online shop and black market.
Governments basically don't care what you are using to do business with or with what currency. Their only priority is that you pay your tax at the end.
Black markets are a different thing as they are operating on a completely illegal ground according to the law. They operate outside the regular system where governments can't do anything about.
I personally don't mind paying tax, but the problem is the amount that is being taken from you. Here the income tax sits very close to the 45% mark. I find that complete theft.
In that matter I can't blame people not declaring any of their Bitcoin related income to their local tax agency. It's pathetic as we already pay a massive amount of tax, but still the government is chasing you down.
