Planning Theory = Solving Social Problems?

It's funny that alleviating poverty and social divides has been the talk of the town during the Venice Bienalle. There were heated arguements about the whole bienalle being a failure, as it only showcased urban policies and nothing architecture. A few question thus arises:

1. To what extend is architecture part of state level policy planning?
2. To what extend can architecture affect the social outcome of the city or villages?
3. To what extend should architects play politicians?

I guess these are very pertinent questions that we should try to answer and I can sadly say that most of the time, despite all the plannings and stuff, the social model may still fail. It's a hard slap on our profession, but I guess it may be the harsh reality that planning do not always materialise as how they plan. I guess we should go back to basics about serving people at the most basic and personal level. Now that I am writing a paper on urban problems, it is so easy to sink into planning theory or statistics. I am very interested and concerned about solving social issues in an architectural sense but whenever I ask myself when was the last time I actually volunteered and cared for the needy, it seems that my aims and actions do not match.