If tax rates increase in the future (highly likely based on historical data), or if your tax rate in retirement will be higher than your tax rate now, a Roth IRA could be a banner idea. Investors who expect to have a higher tax rate in retirement have the most to gain with a Roth IRA, because you pay lower taxes on contributions now to avoid higher taxes on withdrawals later.
This is particularly true for younger investors. The younger you are, the more earning potential you have and the more chance your income will be higher at retirement. Put another way, the greater the difference between your income now and your income in retirement, the more advantageous a Roth IRA can be.