Because you know damn well that humans with very low cognitive or social intelligence (newborns, mentally retarded, down syndrome, aspberger's) are guaranteed these rights, simply by way of being OUR species in the 21st century. Such people used to be butchered or left to die on a hill. Was that wrong? Today we condemn it. Where does "cognitive ability" = not property fit into
einstein:table as IQ57:dog?
I have a much more simplified and imo consistent standard of property and respect: Is it a living creature or not?