Yeah that's the point. Spammers have an infinite desire to make more spam, so statistically most LLM writing is garbage.

Readers are making this connection from their own experience. All these tells just associate it with garbage.

In the before times, sending a formal document full of typos and errors would show you didn't bother to proofread, now having a doc full of lazy "LLMisms" also looks like you were too lazy to proofread.