My impression is just that people are much less inclined to do so than they would be if there was a section explicitly for project ideas.
Creating additional sections increases complexity. Creating additional section for things that could be solved via a thread in discussion or a Wiki page, seem like a bad idea to me.
This article is something that has been in my head for a while. I hadn't planned on doing a write-up so soon. I wanted to take the time to a) refine my ideas and b) figure out how to express them clearly before posting. But the recent post Less Wrong lacks direction made me change my mind. My thinking now is that I overestimated the downside (wasting peoples time with a less than fully thought out post) and that there's enough value to justify posting a rough draft now.
LessWrong has been one of the most amazing things I've experienced in my life.
Easy
Harder