>>76602329 (OP)
>a good thread died for this
to give you a Good Faith answer, it's because they sincerely believe people that eat animal products are ontologically Evil, making a conscious and explicit choice to torture and murder "our fellow creatures."
You'd be an asshole too if you thought you were talking to someone that was openly, proudly immoral. They see normal people the same way normal people see pedophiles, conservatives, mass murderers, etc.
