It’s not a satisfactory answer, but ¯\_(ツ)_/¯
Sharing some anecdata, because I enjoy when others do.
I've got some very dear friends born in a highly prescriptive culture where credential-ism runs deep, being an intellectual is extremely valued -people are often denied leases due to their non-academic status- and authority figures and strangers get the "Mrs." and "Mr." treatment for years after you've met them. Early on in our friendship we would discuss and rant about everything and anything. We would often talk about my attitude of trusting no one and how I believe there are, truly, no experts, in the colloquial sense of the word. We've often had late-night discussions about my "stubborn and deeply misguided attitude", about how it's wrong that the only experts I trust are those who deeply distrust their own abilities, instincts and continuously attempt to disprove their own claims.
Shockingly, they defended the aforementioned views until many of their countries top virologists and they themselves, often and loudly, shared their opinion on covid-19 around March, April and May: covid-19 was nothing special, national mortality trends were unaffected, their country is rich and they had a high number of ICUs, it was basically just like the flu and nothing to worry about. Then, as we all know, shit hit the fan and we saw cooling trucks being turned into mortuary vehicles. I simply told them what I've always told them, and for the first time since we're friends they nodded with some sadness in their demeanour: trust no one, acquire evidence, make your own judgments, try to find hidden risks and the only so-called experts worth trusting are the ones who, in their own words, publicly and candidly express their skepticism towards their very own claims and try to help you reproduce their methods and conclusions.
Turns out the answer is math ;) more specifically stuff which didn't exist back then.
Anyway, according to Wikipedia: "Some mathematicians and historians, such as Carl Boyer, hold that Zeno's paradoxes are simply mathematical problems, for which modern calculus provides a mathematical solution.[6] Some philosophers, however, say that Zeno's paradoxes and their variations (see Thomson's lamp) remain relevant metaphysical problems.[7][8][9]"
So it seems like a few people are still wasting their time with this.
(I found LW/rationalism through philosophy circles, incidentally)
Sadly, I am not a comedian.
You can't simply extrapolate from finding one mistake in a book to declaring the whole book wrong. Likewise, you can't extrapolate from finding few bad publications to "everything is crap". I'm not trying to claim journalists are all good or even consistently good. But believing they are always bad is the same logical fallacy as believing they are always good.
So the situation is bad enough when I am encountering a new source. But if I'm already familiar with a source, and it's consistently wrong about the things I know, then I can only be even more suspicious of everything else they say; and sadly, an awful lot of publications do fall into that category. Finding a mistake in a book does make it more likely that it contains other mistakes, and it does make any given fact in the book more likely to be wrong.
If you can only check one thing and it's wrong, then it is entirely and clearly irrational to assume that everything else is correct.
It's not fully defensible to assume that it's 100% wrong either. Just by plain statistics you may assume almost anything must have some correct portion.
What's rational is to make as few assumptions as possible, and where guessing or informed guessing is necessary, use only the information you actually have. That means back to the beginning, if you can only evaluate one part, and it has a many errors, then that is the only thing you can use to make any assumptions about the rest, unless and until you get actual credible assertions about the rest from someone else who are themselves credible in that domain.
(If you want to read more about this then google "single observation unbiased estimator")
That's exactly the wrong kind of extrapolation I'm pointing out. If you found a flaw in one chapter, the book can be trash, and the chance of it being trash is definitely higher than without any other data, but whether the absolute chance of it being trash is sufficiently high enough can only be determined based on the nature of the flaw, and even then, the confidence for that conclusion can't be really that high.
Determining whether a source is trustworthy is an ongoing process: you're seeing one portion where you have some expertise or evidence and then another portion where you don't. You have to extrapolate from what you can validate to whether what you can't is valid.
The complaint behind Gell-Mann amnesia is that we're too quick to dismiss clear evidence that a source is untrustworthy, that we have a bias towards trust.
To put it in perspective, let's imagine the opposite, call it Crank Awareness. If you see a document and it's laid out poorly, uses weird boldface, all caps, colors and blinking text, you'll, at the very least, get the impression it's written by a crank before you even start reading.
> But believing they are always bad is the same logical fallacy as believing they are always good.
Again, this comes back to the problem of strict logical reasoning vs. treating trust as a larger process. We have limited resources to evaluate sources, so we're stuck making fallacious generalizations when we need to make a decision based on our sources. What we want in the long run is to incentivize authors to exercise care and diligence.
That would indicate we should punish known bad information by deprecating the authors. So another way of reading Gell-Mann amnesia is that readers aren't doing this. They're seeing stuff that they know is wrong and continuing to patronize the publications regardless, thus authors can be untrustworthy and still collect a paycheck.
Well then why did you write about liking the book and whether it's good as the cause of disagreement? That's a very very different thing from whether the book is an accurate source!
Even a specific section you prove to be wrong can still be good.
"That was a super interesting book, it brought up lots of ideas and explanations, lets discuss what parts if any we think are true." !
Folks call out information and facts as fake news, not apply healthy skepticism but a rejection of all knowledge and then at the same time falling for hoaxes.
The whole country needs to take a gap year and learn the scientific method.
Problems only really come in when ignorant people read too many stories and start to think that how they present things is actually real. And some people who know a particular area very well may find whatever the story does too patently absurd to suspend disbelief.
Sometimes books about magical properties of crystals get their geology right. Sometimes they get it wrong.
If I apply your superficial filter I essentially give up my ability to convey the difference to your friends.
If I ignore your filter and pay attention to the entirety of each book, it's trivial for me to help them separate wheat from chaff. (Or at least chaffy-wheat from pure chaff.)
Imagine I give you a dictionary purporting to contain descriptions of the referents of the following words: (I assume you know what a sprint is, but not a bilparyoti or a zambungar)
* sprint - to run at a rapid pace for a short distance
* bilparyoti - a kind of bright blue butterfly, found in Congo-Brazzaville
* zambungar - a muddy colour, specifically that created when a landslide enters a clear river
Now, based on knowing that 'sprint' is 'correct', what is your probability, posterior to being supplied the dictionary, that you know what a 'bilparyoti' references?
Now, imagine that I tell you that the 'bilparyoti' is wrong and you are able to be convinced that the 'bilparyoti' is wrong. Is your prior for the accuracy of the 'zambungar' reference the same as the posterior after being supplied the information about the 'bilparyoti'?
Matticus, there, presumably laments the fact that the zambungar accuracy probability has not moved. Rationally it should move towards zero. By varying amounts, certainly, but towards zero. With his friends, P(zambungar_correct | bilparyoti_wrong) = P(zambungar_correct|bilparyoti_unknown), truly a situation worthy of wailing and gnashing of teeth.
Granted. But OP seems to be at the other extreme which is equally problematic:
> Everyone reads a book, everyone but me likes it.
That strongly implies a boolean value judgment to me.
I wish LW-style rationalist circles didn't attract such obnoxious people, because I don't know of any other collection of people who recognize and try to adjust for things like this.