It seems hard to maintain civil political discourse in an environment where the discussion is public and participation is largely open to all. I think this is to some extent because when we think of discussion, we think of answering questions like "what should we do", but without privacy and barriers to entry, discussions enter the other realm of politics where the main question is "how do we get it done". The former requires openness to self-doubt, which in the latter context is harmful to achieving goals.