That's because it isn't just about ideas, it's about power. Politics and government now are not about coming to consensus solutions that everyone, or at least everyone but a small minority who just wants to game the system, can live with. Politics and government now are about imposing on everyone whichever set of ideas gets a slim 51% majority. That isn't the way it was supposed to work.
I personally would like to see a Constitutional amendment that would require a 2/3 majority in both houses of Congress to pass any legislation, and a 3/4 majority required to override a Presidential veto. That would at least require some amount of bipartisan consensus, and therefore some amount of actually somewhat reasonable debate instead of just shouting back and forth, before a public policy was imposed on everyone.