Participating in bigthink is clunky because of the 'quick thought' / 'response' distinction.  Ironically, the idea of 'joining the conversation' and contributing something substantial is more difficult than making a quick, uncritical 'quick thought'. 

Regular Web forums work better because they have all of the responses (re/re/re) displayed in a text-based branching map.  Bigthink pages could do this, but make it better with less text reliance and more graphic based design.