I partly agree about letter counting being an unfair test for the raw LLM. But I was thinking of reasoning models interminably rationalizing their incorrect first hunch even after splitting the string in individual characters and having all the data needed in a digestible format before them. Similar to, as you say, conspiracy theorists stuck in motivated reasoning loops. But - are these latter behaviors instances of human intelligence at work, or examples of dysfunctional cognition, just like people's incoherence in cases of stroke or inebriation?
The other example I mentioned is something I've encountered a few times in my interactions with Gemini 2.5 pro, which was literally in the same response plainly claiming that this-or-that is possible and not possible. It's not a subtle logical fallacy and this is something even those conspiracy theorists wouldn't engage in. Meanwhile, I've started to encounter a brand-new failure mode: duplicating an explanation with minor rephrasings. I'm sure all of these will be issues will be ameliorated with time, but not actually fixed. It's basically fixes on top of fixes, patches on top of patches, but once in a while the whole Rube Goldberg nature of the fix will shine through. Just the way once in a while Tesla FSD will inexplicably decide to point the car towards the nearest tree.
Yes, humans have their own failure modes, but internal coherence is the effortless normal from which we sometimes deviate, whereas for machines, it's something to be simulated by more and more complex mechanisms, a horizon to strive towards but never to reach. That internal coherence is something that we share with all living beings and is the basis of what we call consciousness. It's not something that we'll ever be able to formalize though, but we will and should keep on trying to do so. Machine learning is a present day materialization of this eternal quest. At least this is how I see things; the future might prove me wrong, of course.