I think the question is valid. Why should a human have a moral responsibility towards non-humans, while a cat doesn't have a moral responsibility towards non-cats, just because the human is capable of making moral judgements? Is there any analogous situation where capacity engenders responsibility? Are gorillas more responsible for how they use their strength, since they're stronger than humans?
>Being capable of that is, arguably, the sole thing that meaningfully separates us from the (real or simulated) fruitfly.
That's a bit of an extreme hyperbole, don't you think?
It would be a great starting point if human felt moral responsibility towards other humans, before we take on the matter of ethics towards non-humans, simulated fireflies or LLMs. Yet here we are.
> Why should a human have a moral responsibility towards non-humans, while a cat doesn't have a moral responsibility towards non-cats, just because the human is capable of making moral judgements?
Because as a human you recognize patterns in other animals that are similar to ours - the deepest pattern being alive - so you can project your feelings over them. This is also called empathy, and some in our kind lack it completely, but I would dare to say that is globally one of the defining traits of the human species.