>>believe as I do that income shouldn't be taxed at all?
Many corporations and wealthy individuals do pay little or no income tax.
http://www.nytimes.com/2013/05/21/business/apple-avoided-billions-in-taxes-congressional-panel-says.html?pagewanted=all

The US income tax was instituted to finance the Civil War. As with most taxes, when the justifying purpose disappeared, the tax remained.
When I last looked there were a couple of states without income taxes, but I'm not sure if they're still hanging in there.
I can't envision what no income tax would be like and at my age I'm fairly sure that I'll never find out, but the present tax code discriminates badly against low and middle income taxpayers and should be changed.