I agree that theoretical-sciency-mathy-insightful stuff is less common now than when Eliezer was writing posts regularly. I suspect this is largely because writing such posts is hard. Few people have that kind of knowledge, thinking ability, and writing skills, and the time to do the writing.
As someone who spends many hours writing posts only to have them nit-picked to death by almost everyone who bothers to comment, I appreciate your advice to "express small disagreements in 'IAWYC but' form."
As for your suggestion to downvote posts that "don't present non-obvious new material," I'm not sure what to think about that. My recent morality post probably contains only material that is obvious to someone as thoroughly familiar with LW material as yourself or Phil Goetz or Will Newsome or Vladimir Nesov or many others, but on the other hand a great many LWers are not quite that familiar, or else haven't taken the time to apply earlier lessons to a topic like morality (and were thus confused when Eliezer skipped past these basics and jumped right into 'Empathic Metaethics' in his own metaethics sequence).
I enjoyed your morality post, as I do most of your posts, and certainly wouldn't accuse it of not presenting non-obvious new material.
More and more, LessWrong's posts are meta-rationality posts, about how to be rational, how to avoid akrasia, in general, without any specific application. This is probably the intended purpose of the site. But they're starting to bore me.
What drew me to LessWrong is that it's a place where I can put rationality into practice, discussing specific questions of philosophy, value, and possible futures, with the goal of finding a good path through the Singularity. Many of these topics have no other place where rational discussion of them is possible, online or off. Such applied topics have almost all moved to Discussion now, and may be declining in frequency.
This isn't entirely new. Applied discussions have always suffered bad karma on LW (statistically; please do not respond with anecdotal data). I thought this was because people downvote a post if they find anything in it that they disagree with. But perhaps a lot of people would rather talk about rationality than use it.
Does anyone else have this perception? Or am I just becoming a LW old geezer?
At the same time, LW is taking off in terms of meetups and number of posts. Is it finding its true self? Does the discussion of rationality techniques have a larger market than debates over Sleeping Beauty (I'm even beginning to miss those!) Is the old concern with values, artificial intelligence, and the Singularity something for LW to grow out of?
(ADDED: Some rationality posts are good. I am also a lukeprog fan.)