> If they're just collecting data to train LLMs, these seem like exceptionally poorly written and abusive scrapers written the normal way, but by more bad actors.

Right, this is exactly what they are.

They're written by people who a) think they have a right to every piece of data out there, b) don't have time (or shouldn't have to bother spending time) to learn any kind of specifics of any given site and c) don't care what damage they do to anyone else as they get the data they crave.

(a) means that if you have a robots.txt, they will deliberately ignore it, even if it's structured to allow their bots to scrape all the data more efficiently. Even if you have an API, following it would require them to pay attention to your site specifically, so by (b), they will ignore that too—but they also ignore it because they are essentially treating the entire process as an adversarial one, where the people who hold the data are actively trying to hide it from them.

Now, of course, this is all purely based on my observations of their behavior. It is possible that they are, in fact, just dumb as a box of rocks...and also don't care what damage they do. (c) is clearly true regardless of other specific motives.