Answer: This policy was meant to be a pressure for China to become a democratic country and to make the U.S. be seen as an role model. It was an ideological battle that USA had to grant the propaganda was being made in the right way, so they would show the strenght of their policies in an economical and social way. The biggest disadvantage was not being able to participate on tradings with a country that was changing and growing so fast it was almost becoming the largest market in the world. Economically, the U.S. had to think again on their strategies or they would face a fierce rival.
This strategy was proven to be useless since USA opened up in the 1970's for trading with China again, and this country continues to develop its economy even having a communist government. The socialist market policy didn't lead to democracy as the U.S. thought. Having this in mind, in my opinion there's no point in mantaining this kind of thought that only shows the American dream is to conquer countries by imposing their way of thinking and considering only their point of view as the right thing to do.