Some would say what is wrong with an SFM. The first point is the long term cycle and adjustment that comes from the cycle. We have seen this in post war countries after the world war that took the influence of the sicle and the hammer and created SFM's. In which when those countries went through cyclical adjustment their economies boomed then busted. During those busts the US was able to create massive capital inflows as they had to borrow money from the US to keep going after the adjustment cycle. We can see this exact historical precedent playing out today. However, in a much more brutal fashion. As the Us did not have and does not have SOE's that conquered the downed countries that created SFM's. Along those lines at that time it was in the best interest of the US to stop communist countries from using their SOE's to conquer these countries while they where in their cycle adjustment troughs. However, today there is no one to stop the communist from conquering the US and other countries once it goes through a cycle adjustment after a possible SFM.
This then can become a very devasting affect on the US economy. Much like we have seen via the US legislation just helping service industries be created. Much less forcing them to be created in a full scale SFM. As such an SFM is an economic destroyer when there is no country to protect from Communist SOE's or Soverign Wealth funds after the cycle adjustment process.
Along with that the inflation rate after the adjustment cycle can create a huge affect on the tax rate. Also forcing many to be dependant on those SFM's for jobs and then most things start to branch out from there.