I pay taxes because of peace of mind. I think OP is talking about 2 different things: good privacy, and being able to spend 6 figures. Those two aren't compatible, you can only have one of the two (legally).
The biggest problem is that most people don't have a clear mindset about who their "enemy" is. Who they want to hide from.
Is it really a huge problem for them that the online shop ABC won't accept their payment?
Or is it that the government's agencies will link the Bitcoin to them and see that they haven't paid taxes and catch them.
Because for me it's clearly the fear of the latter.