That the most important application of improving rationality is not projects like friendly AI or futarchy, but ordinary politics; it's not discussed here because politics is the mind-killer, but it is also indispensible.
On a more specific political note, that there are plenty of things government can do better than the market, and where government fails the people the correct approach is often not dispensing with government but attempting to improve government by improving democracy.
I know that both of these, especially this last, go against what many here believe, and I don't intend to get into a detailed defence of it here - it's not exactly a fresh topic of debate, and it's not in line with the mission for this site.
the most important application of improving rationality is ... but ordinary politics
True because good policies can have vastly differnet outcomes than bad policies.
there are plenty of things government can do better than the market
And plenty of things the market can do better than the government.
What do you believe that most people on this site don't?
I'm especially looking for things that you wouldn't even mention if someone wasn't explicitly asking for them. Stuff you're not even comfortable writing under your own name. Making a one-shot account here is very easy, go ahead and do that if you don't want to tarnish your image.
I think a big problem with a "community" dedicated to being less wrong is that it will make people more concerned about APPEARING less wrong. The biggest part of my intellectual journey so far has been the acquisition of new and startling knowledge, and that knowledge doesn't seem likely to turn up here in the conditions that currently exist.
So please, tell me the crazy things you're otherwise afraid to say. I want to know them, because they might be true.