It's not particularly hostile. It's using an example to demonstrate that someone who sees an action as unethical won't be super hyped about you asking them to spend their time assisting you in doing something they find to be unethical, especially after you insult them for thinking it's unethical.
> couldn't easily use it to shish kebab your cat
This seems like an unnecessarily hostile response, kind of inline with what the OP mentioned.