I cannot pay my tax in such place with bitcoin, when I don't earn in bitcoin. Assuming, I am paid in bitcoin, I don't see it as any problem to me. My bitcoin is very precious to me, so I will rather use it as an investment than giving it to the government.
If I have bitcoin and my government accepts bitcoin as a tax payment method, I will still not use my bitcoins to pay tax.
Because if I am not careful, I will break my privacy to tax governmental agency. With Bitcoin, I have my own bank and privacy if I have good practice. Use my bitcoins to pay tax, is one of bad practice, that I will not do.
I understand your point of view, this is something I also thought about.
However I believe that if you are a experienced Bitcoin user and with good practice like you said. You can find a way to not let them know.
But of course, it could be just an illusion, and that they're trying every means possible to tax you and report any activity they might find suspicious.