Let's read the article for a moment.
Excerpt:
It's still an tax on wages and salaries which is completely unconstitutional, anti-American, anti-prosperity and downright evil. It's nobodies business how much money I earn, especially the criminal government.
That postcard is still evidence that can be used against yourself which is a violation of the 5th Amendment. You will still need a massive bureaucracy to make sure people aren't lying on that card and armed agents to go after people that do.
Scrap the evil income tax altogether and don't replace it with anything. If the government can not raise enough money with excise taxes and tariffs they can always ask for voluntary donations.