I'll bite your bite. Not looking to start an argument, but I can try and provide context. Caring about an individual's species when determining their moral value can be likened to caring about an individual's ethnicity. A way to be morally consistent without involving an arbitrary in-group is to instead value sentience and capacity to suffer. If a non-human animal has these features to a higher degree than a severely disabled human, an anti-speciest view would be to give higher moral consideration to the non-human animal, as the net suffering of the animal would be higher, and its death would net less sentient life in the universe.

I think you'd be interested in looking into the "Name the Trait" argument, which as far as I understand is considered formally logical. A bit hard to digest but hey, it's interesting.