Here's a short list of what was once (and some still are) considered "human nature" or the "natural order": Race discrimination, Religion discrimination, Gender discrimination, Sex discrimination, Age discrimination, Weight discrimination, and so on... Animal discrimination is an extension of the mentality that allowed (allows) the above to go on unquestioned because it's "human nature".But lobsters apparently taste good, I've never had one, so people do it anyway. This is human nature. The end.
It's called 'speciesism', right? I took a great philosophy class last year where we had some great lectures on the moral standing of non-human animals. Peter Singer's piece on animal liberation was part of the reading. He argues that non-human animals are morally not different than human animals, because they are equal in suffering, intelligence and other things. Why not treat them as morally equal? It's a very strong argument. My professor made the counterargument that Singer conflates two different kinds of equality: moral equality and factual equality. We humans are not all the exact same human (factual equality) but we do all have the same moral standing (moral equality). Moral equality is not dependent on factual equality: people who are factually better (e.g. talented / smart people) don't have a higher moral standing because of it. Hence, just because we're factually equal to animals in important regards (the ability to suffer, for example) is not a logical argument for equal moral standing. Have you read Peter Harrison's Do Animals Feel Pain? It seems up your alley.
Indeed. Which is why Wallace takes the masterful unassuming tone that he does. It's, quietly, an essay of unparalleled brilliance. To be able to come down so firmly on a controversial issue without ever giving the hint of offense is impressive.