I don't think he ever assumed no benefit, but rather the benefits are so overblown by the sales tax pitch he's bringing it into perspective with what would be reality.
It wouldn't/couldn't be the near tax free nirvana with 20 to 30% cheaper goods and services that they claim. The fact they have to be deceitful about that and the rate itself is proof enough.
At this point, attempting to assign any sort of cost/benefit ratio to the NRST is meaningless.
Until the ideas congeal into proposed regulations (first, a Law is passed, then the regulations get promulgated - that's the way a Law is enforced - through the framework of regulations for enforcement of the Law) ...
... it is going to be almost impossible to figure out the benefits to various classes of current taxpayers.
Without going through every single post here, I doubt that there has been very much intentional deceit, on either side. The key point to the whole NRST is the elimination of the IRS - so it is much more important to focus on that as the one overriding benefit that will positively effect every class of current taxpayer.
And because of that, it is important to make certain that the IRS IS eliminated as a part of the overall push to implement a NRST. There is a Bill in both the House and Senate to amend the Constitution to repeal the 16th (I think that's the IRS Amendment) Amendment and efforts should be focused on that, with the NRST to be part of the solution to the elimination of the IRS.