Most healthy intellectual blogs/forums participate in conversations among larger communities of blogs and forums. Rather than just "preaching to a choir" of readers, such blogs often quote and respond to posts on other blogs. Such responses sometimes support, and sometimes criticize, but either way can contribute to a healthy conversation.
If folks at Less Wrong saw themselves as a part of a larger community of rationalists, they would realize that most rationalist authors and readers are not at Less Wrong. To participate in a healthy conversation among the wider community of rationalists, they would often respond to posts at other sites, and expect other sites to respond often to them. In contrast, an insular group defined by something other than its rationality would be internally focused, rarely participating in such larger conversations.
Today at Overcoming Bias I respond to a post by Eliezer here at Less Wrong. Though I post occasionally here at Less Wrong, I will continue to post primarily at Overcoming Bias. I consider myself part of a larger rationalist community, and will continue to riff off relevant posts here and elsewhere. I hope you will continue to see me as a part of your relevant world.
I worry a little that Less Wrong karma score incentives may encourage an inward focus, since karma is so far only scored for internal site activity.