This post is a half-baked idea that I'm posting here in order to get feedback and further brainstorming. There seem to be some interesting parallels between epistemology and ethics.
Part 1: Moral Anti-Epistemology
"Anti-Epistemology" refers to bad rules of reasoning that exist not because they are useful/truth-tracking, but because they are good at preserving people's cherished beliefs about the world. But cherished beliefs don't just concern factual questions, they also very much concern moral issues. Therefore, we should expect there to be a lot of moral anti-epistemology.
Tradition as a moral argument, tu quoque, opposition to the use of thought experiments, the noncentral fallacy, slogans like "morality is from humans for humans" – all these are instances of the same general phenomenon. This is trivial and doesn't add much to the already well-known fact that humans often rationalize, but it does add the memetic perspective: Moral rationalizations sometimes concern more than a singular instance, they can affect the entire way people reason about morality. And like with religion or pseudoscience in epistemology about factual claims, there could be entire memeplexes centered around moral anti-epistemology.
A complication is that metaethics is complicated; it is unclear what exactly moral reasoning is, and whether everyone is trying to do the same thing when they engage in what they think of as moral reasoning. Labelling something "moral anti-epistemology" would suggest that there is a correct way to think about morality. Is there? As long as we always make sure to clarify what it is that we're trying to accomplish, it would seem possible to differentiate between valid and invalid arguments in regard to the specified goal. And this is where moral anti-epistemology might cause troubles.
Are there reasons to assume that certain popular ethical beliefs are a result of moral anti-epistemology? Deontology comes to mind (mostly because it's my usual suspect when it comes to odd reasoning in ethics), but what is it about deontology that relies on "faulty moral reasoning", if indeed there is something about it that does? How much of it relies on the noncentral fallacy, for instance? Is Yvain's personal opinion that "much of deontology is just an attempt to formalize and justify this fallacy" correct? The perspective of moral anti-epistemology would suggest that it is the other way around: Deontology might be the by-product of people applying the noncentral fallacy, which is done because it helps protect cherished beliefs. Which beliefs would that be? Perhaps the strongly felt intuition that "Some things are JUST WRONG?", which doesn't handle fuzzy concepts/boundaries well and therefore has to be combined with a dogmatic approach. It sounds somewhat plausible, but also really speculative.
Part 2: Memetics
A lot of people are skeptical towards these memetical just-so stories. They argue that the points made are either too trivial, or too speculative. I have the intuition that a memetic perspective often helps clarify things, and my thoughts about applying the concept of anti-epistemology to ethics seemed like an insight, but I have a hard time coming up with how my expectations about the world have changed because of it. What, if anything, is the value of the idea I just presented? Can I now form a prediction to test whether deontologists want to primarily formalize and justify the noncentral fallacy, or whether they instead want to justify something else by making use of the noncentral fallacy?
Anti-epistemology is a more general model of what is going on in the world than rationalizations are, so it should all reduce to rationalizations in the end. So it shouldn't be worrying that I don't magically find more stuff. Perhaps my expectations were too high and I should be content with having found a way to categorize moral rationalizations, the knowledge of which will make me slightly quicker at spotting or predicting them.
Thoughts?
Yes.
Unless there are anti-epistemologies that are not rationalizations.
The general concept of a taboo seems to me to be an example of a forceful anti-epistemology that is common in most moral ideologies and is different from rationalization. When something is tabooed, it is deemed wrong to do, wrong to discuss, and wrong to even think about. The tabooed thing is something that people deem wrong because they cannot think about whether it is wrong without in the process doing something "wrong," so there is no reason to suppose that they would find something wrong with the idea if they were to think about it, and try to consider whether the taboo fit with or ran against their moral sense.
A similar anti-epistemology is when people believe it is right to believe something is morally right... on up through all the meta-levels of beliefs about beliefs, so that they would already be committing the sin of doubt as soon as they begin to question whether they should believe that continuing to hold their moral beliefs is actually something they are morally obliged to do. (For ease of reference, I'll call this anti-epistemology "faith".)
One of the three things that rationalization, taboos, and faith have in common is that they are sufficiently general modes of thought to permit them to be applied to "is" propositions as well as "ought" propositions, and when these modes of thought are applied to objective propositions for which truth-values can be measured, they behave like anti-epistemologies. So in the absence of evidence to the contrary, we should presume that they behave as anti-epistemologies for morality, art criticisms and other subjects -- even though the existence of something stable and objective to be known in these subjects is highly questionable. The modes of thought I just mentioned are themselves inherently flawed. They are not simply flawed ways of thinking about morality, in particular.
If you are looking for bad patterns of though that deal specifically with ethics, and cannot be applied to other subjects about which truthiness can be more objectively measured, the best objection (I can think of) by which to call those modes of thought invalid is not to try to figure out why they are anti-epistemologies, but instead to reject them for their failure to put forward any objectively measurable claims. There are many more ways for a mode of thought to go wrong than for it to go right, so until some thought pattern has provided evidence of being useful for making accurate judgments about something, it should not be presumed to be a useful way to think about something for which the accuracy of statements is difficult or impossible to judge.
This is a much better explanation of the OPs point than the OPs own posting.