Aside from that, people in aggregate just aren't that bright: I don't want them making decisions much more substantial than what they'll have for dinner, much less voting on issues that affect me.

If you evaluate it on a longer timeline, people achieve a greater political intelligence because of increased voter participation and a quicker policy feedback loop.

Yeah, collectively, humans are still idiots. That being said, we do have a decent amount of technological promise and maybe just enough idealism in our blood to sustain the species. It's probably worth a try.