Human slop, as I like to call it, since so many anti-AI protestors unintelligently use the phrase "AI slop".
In both cases people are using the heuristics they have to deal with the onslaught of slop, nothing wrong with that.
The error rate is what’s wrong. A heuristic which has a high false positive rate is worse than nothing because it trains people to ignore all reports.
It doesn't have a high false positive rate.
I’ve yet to see it claimed here not in error. AI writing has other tells which are far more reliable, use them.
Emdashes as the sole signal is just wrongheaded. Read a piece (a least a little bit of it) to determine if it is slop before calling it AI-slop. Slop is slop but you have to digest at least some of it before the determination can be made.
I sometimes use the Pangram extension for Firefox.