You are correct. A fair tax code will tax all types of income and transactions at the same rate so that there is no incentive to hide, dodge, and evade at the expense of investing in your organization and paying dividends to your shareholders. A smart and far tax code will set the tax rate to be about the same as those of foreign jurisdictions to avoid pushing capital offshore.
If there were a flat (say 15 or 20 pct) tax on income, capital gains, and foreign purchases sold to americans, etc, there would be no way to dodge and no incentive to go offshore, because the tax rates elsewhere are the same, and there's no way to structure a payment or income source in a way that avoids taxation at some point along the money's route. The only way it escapes taxation is if it is flat-out transfered abroad and stays there, at which point it gets taxed abroad at a comparable rate.
But then the tax lawyers would be out of work, and guess who tends to run for Congress?
