I don't think this is about edge cases where someone has successfully disguised the writing to some degree: the current crop of LLMs have some pretty blatant (and frankly annoying) habits by default, ones that are hard to miss once you have read a decent amount of their output. If I had to describe them broadly, I would say they are a collection of habits which are common in certain kinds of persuasive and emotive writing, but are usually applied way out of proportion to the topic at hand, which tends to make the result quite grandiose, overly dramatic, and tiring to read: a LLM will often write a TODO app README like it's a cross between a thriller novel, a political speech, and a bombshell news article. There's lots of specific tics (and just by sheer volume and uniformity almost any habit an LLM picks up is going to rapidly shoot into cliche regardless of its own merit) but this is the general effect which I think is objectionable independent of the source of the text.

I do think the sensitivity to it can vary a lot: it depends a lot on how much and how closely you read the text, and how much exposure you have to LLM writing. Certainly it seems like a lot of people just don't really notice, or at least don't care much.

Pieces that people aren't revolted by will be fine. Readers aren't revolting because of a flood of high quality writing though.

This is very handwavy and dismissive. It is pretty safe to assume that must of us catch it most of the time because the simple fact is so many people just copy and paste whatever the LLM outputs without even trying to edit it or mask that they used one. We’ve all seen so many examples of the exact same cadence and verbiage that we’ve learned how to identify it pretty reliably. The ones who are “slipping past us” are actually putting in the work make not just pasting raw LLM outputs, which is the real issue here. If somebody has edited it meaningfully after the fact then it’s not the same crime.

AI writing just means "writing I don't like" now. Just like Nazi means whatever and whoever I politically disagree with. Words have lost their meaning.