[Abbreviated argument.]

In the most pragmatic terms possible, this is why throwing more stigmatized groups under the bus is an inherently self-defeating strategy. As long as society has a category of “okay to abuse. Okay to hurt,” devalued, sentient beings are at risk of being demoted into it. When that isn’t challenged on all fronts, the prison just keeps getting bigger. 

So I’m going to be a bit pedantic but I hope my larger point gets across in this stream of consciousness.

If I understood, your fundamental assertion is that human animals are subjected to a legal system they did not agree to be bound by and have no recourse against. This parallels the way humans used to inflict their legal system on other animals. I agree.

I disagree with some of your intermediate points. My impression is that you're trying to dedicate your energy to fixing a whole range of important things that are systemically broken, though, so I'll try to keep this short.