Oh, we're arguing definitions. Okay.

inhumane: without compassion for misery or suffering; cruel

cruel: willfully causing pain or suffering to others, or feeling no concern about it

You cannot treat an LLM inhumanely, definitionally.

Anyways, when one swears at someone it's typically meant to berate or belittle that person - to inflict some sort of emotional pain. That's the sense I intended when using the word, which is why it fits as a response to what you're saying, and why I would say "don't be nasty to a LLM" has little to do with the LLM itself.