Gary Johnson likes fairtax just bc you eliminate income and the IRS doesn't mean you quit taxing. Eliminates a bloated organization in favor of a smaller org to just audit original merchandise sellers not everyone. And every mustachian should be in favor of sales tax over income tax.
A pure mustachian, one who works maybe 7-10 years and then retires, would likely net receive more benefits from the federal gov't over a lifetime than they pay in taxes.
SS time, please take almost 90% of your 35 year average income, even though you only worked for 10 years, that middle class guy who worked 40 years can subsidise you by only taking 32 percent!
Medicare? Well, you didn't pay much, but sure, take it at no reduction in benefits! Want cheap health insurance before? Sure! take some free expanded medicaid or ACA tax credits, health care is cheap anyway.
Hobby income? earned income credit all around, we dont need it!
Capital gains & dividends? no you poor thing, you didn't have enough, we won't tax that... etc.
From an ideological standpoint I agree with a consumption tax, from a selfish standpoint, maybe things are good as they are.