Yeah, I waffled about this and ultimately decided not to say that, but I'm not confident.

I'm not really clear on whether what people are really asking is (e.g) "does X deserve moral consideration?," or whether it just happens to be true that people believe (e.g.) that it's immoral to cause pain, so if X can experience pain it's immoral to cause X pain, and therefore X deserves moral consideration.

But I agree with you that if the former turns out to be true, then that's the right question to be asking.

Admittedly, my primary reason for being reluctant to accept that is that I have no idea how to answer that question a priori, so I'd rather not ask it... which of course is more bias than evidence.