All getting together and deciding on something is the rosy version of how our democracys laws come to be or how we decide to go to war, for instance. It feels like people "all got together" if you accept that the apparent consensus of the public you perceive through news and other media is a real reflection of their sentiments rather than a rudder on the boat of public opinion. See Chomsky's manufacturing consent. The "public discourse" is really always a mix of propaganda and real ground truth, and they're hard to separate, but there are certainly strong influences exerted by organized groups.