Why do bots have flawed english? Seems like with LLMs being a thing they would not.

“Bots” is a cover term for both purely automated scripts, and for human posters who are using some kind of tools to post more efficiently in order to manipulate discourse.

In this case, it’s obvious that a lot of Russian state-actor employees, for instance, are not passing their writing through an LLM, but rather are just quickly vomiting out a comment in their imperfect English. Exposés of Russian troll factories show that a lot of these employees are young university-educated people who only want the money, and don’t have strong feelings for the propaganda they are posting, so they half-arse it.

They're not necessarily bots in the sense of automated accounts but the older troll farms with a bunch of people just clicking away.