But you continue to fail to recognize that losses in one are are compensated in other areas such that your net position will be positive.
How would you know that?
Yes, going forward, earnings from savings may accumulate tax free, a good thing, but currently so can assets that are not traded, or are traded into equivalent holdings. I can hold an investment in IBM or GE, a tax efficient index fund, or an apartment complex for 20 years without being taxed on anything but their dividend, or net income. I can decide when to take a gain or a loss on the holding, and be subject to the as low as 15% capital gains tax (again only on the difference between basis and realized value), or just borrow against the asset and pay no tax. The CG rate can change of course, but the public servants would be facing down the rich guy as well as the middle class guy if they wanted to change the capital gains rate - and hence would be less likely to pursue this option (as their campaign contributions would vanish). And the "FairTax" would never recognize a capital loss.
The "FairTax" favors the low asset wage/income earner, at the expense of the high asset holding individual at the time of enactment. Typically, the new worker vs. the prudent individual nearing or at retirement. So there are winners and loosers in this contest. I would be a looser, and so would vigorously (old guy vigor) oppose the change.