This is gish-galloping, to properly address your points, every paragraph would require 3ish paragraphs, so I’d have to spend the better part of 2 hours responding, which is totally unreasonable to expect in a forum like this with a stranger you have no personal attachment to.
From what I gather, your main issues are social ostracization and false equivalencies. Using social norms to drive your moral decisions is obviously problematic, you can think of a ton of atrocities committed by humans when those atrocities were socially normalized. People aren’t born evil, with an intent to cause harm. They’re taught to be ambivalent, and can perpetuate atrocities through apathy.
As for the idea that there’s some false equivalence, you’re misunderstanding the thought experiment. Yes, eating humans is more dangerous than eating chickens or dogs, but that’s a happenstance of nature. It’s possible we could figure out a way to eliminate prion diseases and other harmful effects of cannibalism, and then farming disabled humans who process information at the same level of a cow would be morally permissible to a logically consistent non-vegan.
Of course, essentially no carnists are logically consistent. They use emotion and preference towards certain species to guide their decision instead of rationally considering when it’s okay to harm something (taste pleasure isn’t a high enough bar to inflict pain and death, obviously).
Normative truths are just as foundational as descriptive truths. You use the same logic to get there. I hope you’re intelligent enough to be an epistemological nihilist, so hopefully you know the basis for all scientific and descriptive understanding of the universe is self-evident axioms. The same is true for moral truths. Harm is axiomatically bad in the same way that our senses are accurately able to translate information of an external universe into our brains.
If you disagree with the former, we can’t have moral discussions, and if you disagree with the latter we can’t have scientific discussions. This is how the whole of epistemology functions.
You’re also strawmanning me. Ought implies can, so an animal without an ability to act morally obviously has no moral obligations. I hope you somehow just severely misunderstand the vegan position, and you’re not intentionally spreading misinformation.
Factory farms aren’t us allowing them to sort out their own problems. We spawn billions of sentient creatures into torture boxes every year just to slaughter them when they’re a few months old in brutal and terrifically painful ways.
If you think that’s awesome, keep buying meat, more power to you, you’re just probably a psychopath (though I obviously can’t give you an official diagnosis).
It's almost like a zombie movie for them (startrek.website)