Just want to briefly join in with the chorus here: I'm tentatively sympathetic to the claim, but I think requiring people to spend several hours reading and meditating on a bunch of other content – without explaining why, or how each ties into your core claim – and then refusing to engage with anyone who hasn't done so, is very bad practice. I might even say laziness. At the very least, wildly unrealistic – you are effectively filtering for people who are already familiar with all the content you linked to, which seems like a bad way to convince people of things.

Having skimmed the links, it is very non-obvious how many of them tie directly into your claim about the EA community's relationship with feedback loops. Plausibly if I read and meditated on each of them carefully, I would spot the transcendent theme linking all of them together – but that is very costly, and I am a busy person with no particular ex ante reason to believe it would be a good use of scarce time.

If you want to convince us of something, paying the costs in time and thought and effort to connect those dots is your job, not ours.

I claim that the Effective Altruism and Bay Area Rationality communities have collectively decided that they do not need to participate in tight feedback loops with reality in order to have a huge, positive impact.

I am somewhat sympathetic to this complaint. However, I also think that many of the posts you linked are themselves phrased in terms of very high-level abstractions which aren't closely coupled to reality, and in some ways exacerbate the sort of epistemic problems they discuss. So I'd rather like to see a more careful version of these critiques.

The title of this post did not inform me about the claim "that EAs have collectively decided that they do not need to participate in tight feedback loops with reality in order to have a huge, positive impact -- [and] this is a deeply rooted mistake." 

I came  very close to not actually reading what is an interesting claim I'd like to see explored because it came close to the end and there was no hint of it in the title or the start of the post. Since it is still relatively early in the life of this post you may want to consider revising the title and layout of the post to communicate more effectively. 

The core thesis here seems to be:

I claim that [cluster of organizations] have collectively decided that they do not need to participate in tight feedback loops with reality in order to have a huge, positive impact. 

There are different ways of unpacking this, so before I respond I want to disambiguate them. Here are four different unpackings:

1. Tight feedback loops are important, [cluster of organizations] could be doing a better job creating them, and this is a priority. (I agree with this. Reality doesn't grade on a curve.)
2. Tight feedback loops are important, and [cluster of organizations] is doing a bad job of creating them, relative to organizations in the same reference class. (I disagree with this. If graded on a curve, we're doing pretty well. )
3. Tight feedback loops are important, but [cluster of organizations] has concluded in their explicit verbal reasoning that they aren't important. (I am very confident that this is false for at least some of the organizations named, where I have visibility into the thinking of decision makers involved.)
4. Tight feedback loops are important, but [cluster of organizations] is implicitly deprioritizing and avoiding them, by ignoring/forgetting discouraging information, and by incentivizing positive narratives over truthful narratives.

(4) is the interesting version of this claim, and I think there's some truth to it. I also think that this problem is much more widespread than just our own community, and fixing it is likely one of the core bottlenecks for civilization as a whole.

I think part of the problem is that people get triggered into defensiveness; when they mentally simulate (or emotionally half-simulate) setting up a feedback mechanism, if that feedback mechanism tells them they're doing the wrong thing, their anticipations put a lot of weight on the possibility that they'll be shamed and punished, and not much weight on the possibility that they'll be able to switch to something else that works better. I think these anticipations are mostly wrong; in my anecdotal observation, the actual reaction organizations get to poor results followed by a pivot is usually at least positive about the pivot, at least from the people who matter. But getting people who've internalized a prediction of doom and shame to surface those models, and do things that would make the outcome legible, is very hard.

(Meta: Before writing this comment I read your post in full. I have previously read and sat with most, but not all, of the posts linked to here. I did not reread them during the same sitting I read this comment.)