Another good post of Scott's comes to mind, where he writes:

Suppose there are two sides to an issue. Be more or less selfish. Post more or less offensive atheist memes. Be more or less willing to blame and criticize yourself.

There are some people who need to hear both sides of the issue. Some people really need to hear the advice “It’s okay to be selfish sometimes!” Other people really need to hear the advice “You are being way too selfish and it’s not okay.”

It’s really hard to target advice at exactly the people who need it. You can’t go around giving everyone surveys to see how selfish they are, and give half of them Atlas Shrugged and half of them the collected works of Peter Singer. You can’t even write really complicated books on how to tell whether you need more or less selfishness in your life – they’re not going to be as buyable, as readable, or as memorable as Atlas Shrugged. To a first approximation, all you can do is saturate society with pro-selfishness or anti-selfishness messages, and realize you’ll be hurting a select few people while helping the majority.

I see this as applying to a number of issues. For example, I've considered writing a post where I encourage Less Wrongers that I perceive to be overconfident to be less overconfident. But then it occurred to me that there are other Less Wrongers who I perceive to be underconfident who might be harmed by such a post.

Gullibility feels similar. Ideally we'd have highly intelligent & rational people be more gullible, and less intelligent & rational people be less gullible.