When discussions about such topics are opened on LW, often the logical next step would be to ask about the more general underlying problems that give rise to these situations, instead of just focusing on the arguments about particular problems in isolation. (And even without a concrete motivation, such questions should directly follow from LW's mission statement.) Yet I see few, if any attempts to ask such general questions on LW, and my occasional attempts to open discussion along these lines, even when highly upvoted, don't elicit much in terms of interesting arguments and insight.

Your own points have struck me as on the mark; but I haven't had much to add.

There are some interesting general comments that I could make based on my experience in the mathematical community in particular. I guess here I have some tendency toward self-preservation myself; I don't want to offend acquaintances who might be cast in negative life by my analysis. (Would be happy to share my views privately if you're interested though.) I guess my attitude here is that there's little upside to making my remarks public. The behaviors that I perceive to be dysfunctional are sufficiently deeply entrenched so that whatever I would say would have little expected value.

The main upside would be helping others attain intellectual enlightenment, but although I myself greatly enjoy the satisfaction of being intellectual enlightenment, I'm not sure that intellectual enlightenment is very valuable from a global perspective. Being right is of little use without being influential. In general the percentage of people who are right (or interested in being right) on a given topic where a contrarian position is right is sufficiently small so that the critical mass that it would take to change things isn't there and nor would an incremental change in this percentage make a difference.

The reason why the above point has so much weight in my mind is that despite my very high interest in learning about a variety of things and in forming accurate views on a variety of subjects; I haven't achieved very much. It's not clear whether having accurate views of the world has been more helpful or harmful to me in achieving my goals. The jury is still very much out and things may change; but the very fact that it's possible for me to have this attitude is a strong indication that knowledge and accurate views on a variety of things can be useless on their own.

The best cure against such prideful attitudes is to ask yourself what you have to show in terms of practical accomplishments and status if you're so much more rational and intellectually advanced than ordinary people. If they are so stupid and delusional to be deserving of such intolerance and contempt, then an enlightened and intellectually superior person should be able to run circles around them and easily come out on top, no?

Regarding:

As an illustration, we can take an innocent and mainstream problematic topic like e.g. the health questions of lifestyle such as nutrition, exercise, etc. These topics have been discussed on LW many times, and it seems evident that the mainstream academic literature is a complete mess, with potential gems of useful insight buried under mountains of nonsense work, and authoritative statements of expert opinion given without proper justification. Yet I see no attempt to ask a straightforward follow-up question: since these areas operate under the official bureaucratic system that's supposed to be guaranteed to produce valid science, then what exactly went wrong? And what implications does it have for other areas where we take the official output of this same bureaucratic system as ironclad evidence?

I made a comment that you may find relevant here; I would characterize nutrition/exercise/etc. as fields that are obviously important and which therefore attract many researchers/corporations/hobbyists/etc. having the effect of driving high quality of researchers out of the field on account of bad associations.

Another factor may be absence of low hanging fruit (which you reference in your top level post); it could be that the diversity of humans is sufficiently great so that it's difficult to make general statements about what's healthy/unhealthy.