This wouldn't be the case if Slate Star Codex was still going, or if Eliezer Yudkowsky kept writing, or if Julia Galef was still doing things in public, or if Sebastian Marshall had a greater influence, or if CFAR was actively pushing something at least as effective and clear as CBT, or if any of the rationalist communities or shared houses or organizations weren't, essentially, complete failures at actual community building (not all of them literally fell apart, but if you supply housing and can't keep people around as well as a corporately managed apartment building, I'm not sure 'success' is the descriptor).
The community is so 'rational' that the de-facto leader can write a book about coordination failures and still have the movement centered around the San Francisco Bay Area, despite it being terrible for almost all purposes. Surely, if there is any value in a community, it's that you can solve coordination problems within that community.
But when people talk about the rationalist diaspora, they largely mean the online community. And that community is very, very bad at actually listening to what the leaders of the movement said.
I've never seen so many people so obsessed with looking smart and indulging in the trappings of academia even in casual conversation, and yet be so utterly incurious and mock those who get simple questions of fact correct. It's not that this happens all the time – but if you measure against other, more randomly sampled cultures, it happens more often, not less. Most groups have social conventions and orthodoxies where they simply wouldn't bump into these conversations, so we'd predict that cultures with more frank discussion are going to get more knucklehead-moments. But if the point is to try and actually understand the world, surely you'd see some effort to actually do that, instead of posturing.
I took five minutes to look over a new forum for people in the Slate Star Codex readership – I would have taken more, but that's when I saw a comment saying Kim Jong-Un isn't as bad as people were saying, and was actually a reformer. Suffice it to say, if you laughed at how ludicrous that was, but don't feel like an expert on North Korea, please trust me when I say, if you knew precisely why they would even think something like that it'd be clear your laughter is justified.
As an aside, the Slate Star Codex subreddit is the only place I've seen an actual Ad Hominem argument. Most of the time people think just insulting someone is Ad Hominem, which is extremely imprecise usage. The term formally refers to when someone says, "X says Y, and X is a bad person, so Y is false". In a splash of irony too intense to even comprehend, the 'rationalist' community strongly upvoted someone saying, 'Researching things for yourself is what cranks say! Clearly we should instead prefer to rely on citations like they do in academia'.
I'll admit that moment – with people being so honest about their failures, of engaging in the most notorious logical fallacy to make fun of researching a topic of interest – does sort of help me understand things. I will avoid linking to this because I don't think it's fair to call specific momentary things out and link so people can brigade and argue – I'm sure this person would prefer I use a citation, but alas, I was unconvinced by their amazing rationalist power.
It's also worth saying how many people who've stepped up after the original, more thoughtful founders stepped down, are... less than ideal ambassadors. I recall one episode of The Bayesian Conspiracy where all three hosts seemed to unironically praise the dystopia described in Brave New World, and then not just say it is their preference, but say they never understood why anyone wouldn't prefer that. No effort was made to investigate this – please listen and draw your own conclusions (if you can possibly recall which episode this was – it was a tangent that isn't amenable to simple web searches), and consider how much pride they take in their staggering ignorance of the humans around them in this world. That book does not present an enticing vision to most people, and the many reasons why are not particularly hard to guess.
Various fringe beliefs have become so orthodox that no subpart of the community can meaningfully have discussion about them, even if most people in that community don't believe them. Notably, cryonics and polyamory. I've written about cryonics before, so here, I will simply note that paying to be a lab rat for a technology that has never worked only makes sense if someone actually checks if it worked. Right? I'm not on crazy pills, right? That even the phrase 'lab rats' implies someone is checking the answer, and that's not happening here. You cannot accidentally guess a breakthrough procedure, and presume it works without checking, unless you are prepared to give quite a bit of money to people selling you all sorts of things that definitely have never worked. Preserve all the information you want, at some point you have to actually try the thing. And that's extremely likely to be destructive, so you haven't really fixed the problem.
About polyamory, I will avoid the obvious (because I've learned that calls to not be emotionally abusive to spouses, like, for instance, explicitly announcing to strangers that your partner is disposable to you and you'll divorce them if they stop being worth the effort, fall on deaf ears in the 'rationalist' community) and point out something slightly covert: that, in Eric Weinstein's podcast, an interview revealed that nearly every performer in the pornographic industry has a hard time dating. If honestly, disclosure, and openness to different experiences were all that was needed to be emotionally fulfilled with polyamory, I would guess, considering their status as sex icons, that they'd actually do pretty well. This isn't the case. They're more prepared than anyone, and have sex drives intense enough, I'm led to believe, that their partners are not left wanting. The emotional threat of sexual non-exclusivity is at it's nadir – they're just coworkers they'll see for a day or two. And yet, their troubles are real. I would say it'd be 'rational' to not dismiss the suffering of others (and not finding love is a truer form of suffering than most), and to understand that if an exceptionally well-supported and well-suited cohort cannot manage something, it might not be a good match for hobbyists. I don't think many would disagree with this, and yet the orthodoxy in the diaspora is strong.
The problems with strong orthodoxy's effects on rational thought are far too obvious to point out (you're smart enough to see why unquestioned 'truths' are fishy), and yet I've seen no effort to avoid this. Last I checked, a major member of this diaspora (who runs Thing of Things) was actively attempting to hyper-normalize this outlook.
No normal person would find this community appealing. The core, original writers were good, but without those leaders, there's simply no foundation. The community has collapsed into dysfunction, failed in its few goals, and alienated quite a few people. If there's no room for a hard-charging business person like Sebastian Marshall to get high status, but people constantly complaining about akrasia (lack of ability to do things you want to do) have a solid place, you're going to get precisely the community you'd guess. Every community competes to be a place where people get status, and it's worth explicitly considering not just who gets status, but what their background rate is for status. If you want to have more members of a certain type, they should predict they'll have more status in this group than they'd get elsewhere. So business people leave, neo-Nazis arrive (they aren't high status, heavens no, but it's higher than they'll get elsewhere), there's no high-quality leaders to set a strong tone anymore, and people who can't achieve their goals (but can write about akrasia) are given a place at the table.
There are plenty of nice people in the community. That none of them have been valorized for everyday acts of kindness tells you it's no community at all.