Maybe all of the apparent poverty in our culture's discourse, art, social cohesion, etc. isn't caused by broad tragedies of the commons that make for intriguing blog posts. Isn't the more parsimonious explanation that our culture is now composed of poor critical thinkers who are poorly educated, lack sophistication and nuance, and accordingly have terrible taste? We keep trying to invent these just-so stories for why we keep selecting for horrible, simplistic ideas when so many good ideas already exist. Rather than inventing a hundred different perverse incentive models and technology-changing-the-landscape theories, Occam's razor would favor the explanation that there has been a 'continental drift' in our cultural tastes and maturity. The observation that we keep voting for crappy stuff is best explained by... us preferring crappy stuff.