Moving from a progressive tax structure to a (mostly) regressive one is a bad idea, so I am glad FairTax never went anywhere.

I am all for simplifying the tax code but consumption taxes are the wrong way to go about it.

"Fair tax" is just an attempt to lower the tax rate of higher incomes that get hit by progressive brackets. Same for "flat tax". Calculating the tax rate is easy, the real problem is always to determine what gets taxed. That's where the loopholes are.