The problem with scientific models is their lack of presience regarding human behavior. Scientific models have their uses as a baseline to begin an experiment but if human behavior is one of the variables that can ultimately affect the outcome or conclusion then the likelihood of reliable predictions based on the model becomes much more remote.
One thing we never seem to debate on these threads is what behavior would be caused by the implementation of the FT.
After studying classic economics in college and being a de facto macro-economist for most of my career I have concluded that most academics look for an "efficient market" while successful investors realize that the greatest misconception about markets is that they are supposed to make sense.
So all the anit's rant about the logic of a FT but ignore the behavior that may be attached to it. The IT is like a ball and chain around the entire economy. Freeing up commerce to the point that those doing business have only one decision to make at the time of exchange, whether to buy and spend the tax or not, can only be stimulative IMHO.
You're certainly right ... excellent point!!