The relative dearth of sustainable yet immediate behavioral payoffs coming out of the box leads me to suspect that the people who go into the box go there not so much to learn about superior behaviors, but to learn about superior beliefs.

Bingo.

Excellent analysis throughout, btw, but that bit hits it right on the head.

(In fairness, though, I think it should be pointed out that there's plenty of other good advice to be found on LW. It's only natural to expect that the most popular memes would be ones that have more going for them than mere truth or usefulness.)