Even with the discussion section, there are ideas or questions too short or inchoate to be worth a post.
This thread is for the discussion of Less Wrong topics that have not appeared in recent posts. If a discussion gets unwieldy, celebrate by turning it into a top-level post.
Agreed with Jack about the nuisance value of splitting up not being worth it for the current level of throughput.
If things do get significantly overloaded, a better (though harder to code) answer would be to allow individual users to define filters, and modify the site code to only display posts whose tags match the user's filters.
I think the current level of throughput is low largely because there is no subsection of the kind James is arguing for; maybe there are arguments to be made that these topics are already appropriate in theory, but in practice I think the fear of being off-topic, the fear of being incorrectly perceived as off-topic, and the lack of active priming to post on these topics are inhibiting a lot of potential useful contributions, especially from more cautious members.