I think you are not picking up on how this stuff works to be honest. Or deliberately neglecting to do so. A person who can live on long term capital gains alone is not considered 'poor' by most people.
That was my whole point. THE LOWER INCOME BRACKETS have 0% capital gains, thus a post about how the rate can be as low as zero doesn't really apply when talking about being rich. Would you agree?
The upper income brackets have 15% or 20% long term capital gains and short term capital gains are at NORMAL INCOME RATES (which is up to 35%). Now in 2013 you get to add 3.8% "bonus tax" for Obama care. Also don't forget most states treat capital gains as regular income so throw in another 3% to 11%+ depending on your state. It varies a lot by states so your luck may vary, everything from full income tax rate, to reduced tax, to no tax.
http://taxes.about.com/od/capitalgains/a/CapitalGainsTax.htmSo say you are in the highest bracket (single >$400K taxable income) and live in California and you hold a Bitcoin for 364 days.
Your "low" capital gains rate would be 39.6% federal + 3.8% bonus + 10.5% state = 53.9%. Oh and the fun part is it likely is only a matter of time before IRS treats Bitcoin exchanges like Forex exchanges which means the 60/40 rule comes into play. That will mean even long term trades are taxed at a mix of long & short rates and thus capital gains could be as high as 39.6% (including bonus Obamacare tax) plus state taxes. Worse there is no way to reduce it by holding 365 days or more.
Starting to get the picture? Yes capital gains taxes are lower than regular income primarily because there is no Social Security or Medicaire but if you are making >$108K in regular income those taxes are capped anyways. If you want to make smart tax avoidance strategies (as opposed to tax evasion) you need to drop this "rich don't pay taxes" meme because it is only going to cost you a fortune if you are every rich.
As for flat tax. 60% of Americans pay no income tax in the US. You really think they are better under a flat tax? The top 5% of Americans pay 25% of the income tax you really think they are worse under a flat tax? The flat tax may be fairer but it isn't fairer in the sense most Americans think.