You are right not to rely on people's intelligence, but we are obliged to do so because we are not monarchists and we believe in democracy, or at least we try to.
How sure are you of that? I would bet there's more than one Mencius Moldbug fan on hacker news....
I don't know for sure. And certainly we are not what you call "leftists" in HN. But let me say this on a personal level. I know that people sometimes, all the time, often, certainly, behave stupidly. But I want to believe, ergo I believe, that people can make good decisions, that there is such a thing as "common sense". Looking at the facts sometimes made me sad. Maybe people can't think for themselves, and then they can't choose. But I prefer not to think in terms of peasants and elites, even if history tells me so and Ortega y Gasset tells me how it works. I want to believe that we are capable of governing our lives. I want to believe. Forgive me for expressing not a fact, but the way I think about democracy.