Removing political discussions is in itself tricky since the definition of what is political is subjective. But removing certain kinds of political discussions is even harder to do well, if not impossible. If it's still going to be allowed to post things about housing markets, education, economics, regulation or other areas where social science arguments are relevant. You must also be able to express arguments or submit stories that uses subjects like class or gender. Otherwise you are removing certain perspectives from the discussion in favor of arguments outside those perspectives, which is censorship.
I don't think polarization is the problem, nor even that society is more polarized now than before. In many way it's the opposite. Subcultures and large dividing issues are to some extent a thing of the past. People tend to have less developed views and less experience with other peoples views. Which makes disagreements more personal.