Because there's no point in going through all the steps, but that's exactly where it would end if you absolutely refused to pay taxes and refused to pay fines or go to jail for not paying.
I fail to see how having a gun to your head is in any way true. Can you give any examples of this happening?
Tax evasion is a crime and you should go to jail (you are exploiting the benefits you have received from society). But big companies find tax loopholes all the time and they go to white-collar prisons or get away with it anyways.