> What is it satirizing?

I think it's (partly) satirizing how we feel about ourselves as the apex beings, and as explorers of the cosmos and colonizers. What if we are actually quite subpar, and the actual apex beings in the universe find us so unlikely and disgusting that they prefer to pretend they are not there, thus giving an answer to Fermi's Paradox? They don't want to conquer us, they don't want to have anything to do with us!

But of course, it's also satirizing this alien-as-a-bug idea, so common of early scifi, that the alien is a disgusting mess of antennae or simly appendages. What if we were disgusting to enlightened aliens?

What we can absolutely be sure of is that Bisson wasn't making fun of meat or the human brain, the thought that apparently irked the topmost commenter.