The point of revolution is to change the world, or at least a corner of the world. One could certainly argue that our world today can use a little changing. The world that so desperately needs changing is the world of people, the social world. But society is not a self-existent entity, a life form in and of itself. Society is made up of individual people. Changing the mass of people known as society is a massive undertaking, and likely futile. As far as that goes, changing any one person other than yourself is generally as futile in the long run, unless that person really wants to change. And even then, you don't really change said person. At best you help, you provide guidance, you may point the way and give a gentle nudge along the path every now and again. But real change is typically fueled internally. We change ourselves.
To that end, what better way to change than through the practice of Taiji? If one practices Taiji diligently for a month, his or her understanding of Taiji will begin to change. If one practices for three months, his or her physical and mental structure and nervous system will change in observable ways. If one practices diligently for five years, one's life will begin to show signs of change. If one practices for ten years, one will barely be recognizable from the person of a decade earlier. After twenty years, everything about a person and his or her life will be so dramatically different that he or she will have, and will have had, a positive impact on the world. Hence the world itself will have changed.