There are various people who feel that Lesswrong degraded in the last year. In the same timeframe more and more discussions moved into the open thread model and open threads became weekly instead of monthly.
I suggest to counteract that trend by opening all discussions per default on Discussion instead of opening them in weekly open threads. Having the topics in discussion makes it easy to browse the list of topics and choose the headline that are of interest, even if the thread got opened two weeks ago.
I think the barrier to posting a post in Discussion is higher than posting a comment in the Open Threads, and thus less of them will happen. I also think doing Open Threads on a monthly timescale, instead of a weekly one, will lead to less comments in the open thread.
I think a guide on "This is how you post to Discussion! :D" will be more effective at getting people to use Discussion the way ChristianKI wants than reducing the frequency of the Open Thread posts. (That's an example of what I think a method that increases activity looks like.)
Isn't the barrier a convention? Christian is trying to change the convention.