Why do you suppose that is?
8 years later, and after being exposed as a fraudulent plan, the FairTaxers are still suckering in new converts with misrepresentations of what the rate is, what it would need to be, and how little they know about the potential effects of this radical change.
Hatred of the IRS is not enough to get rational people to support the plan. There are an infinite number of possible plans that all include getting rid of the IRS.
Most of them, including the FairTax, are worse than what they replace.