Believing that a paperclip maximizer won’t respond to the arguments you’re using doesn’t mean that you think that every species has its own values and no values are better than any other.
is to say that there doesn’t exist any relevant perspective from which “no values are better than any other” makes sense. Contrast with the case of “no ice cream flavor is better than any other”, where there does exist such a perspective (that of maximizing ice cream delight by matching people to their preferred ice cream flavors). The claim is that importing any moral intuitions from the ice cream case to the morality case would be a mistake; that purely descriptive interpretations of “every species has its own values” may be true, but any normative content you might read into it (“every species has its own values [that are in some sense proper to it and appropriate for it to pursue]”) is confused.
I think the point of this:
is to say that there doesn’t exist any relevant perspective from which “no values are better than any other” makes sense. Contrast with the case of “no ice cream flavor is better than any other”, where there does exist such a perspective (that of maximizing ice cream delight by matching people to their preferred ice cream flavors). The claim is that importing any moral intuitions from the ice cream case to the morality case would be a mistake; that purely descriptive interpretations of “every species has its own values” may be true, but any normative content you might read into it (“every species has its own values [that are in some sense proper to it and appropriate for it to pursue]”) is confused.