There's a specific carnal aspect to eating meat that I imagine is lost on a lot of people, especially when they don't have firsthand experience butchering animals. For me, it was when I was gutting the first deer I killed. There's this weird thing where you become incredibly conscious of the movement of your internal organs when you are holding another animal's warm entrails. It's almost entirely physical rather than mental, like what it feels like when you meditate on your breathing, except instead of breathing it's the pressure of food sludge sliding down your intestines.

I realized that me and the deer are both just slightly differently-arranged sacks of meat. I always thought I'd have some revelation about the sanctity of life when I killed a deer, but instead I felt an immediate detachment from it, like how I'm just part of an uncaring physical system ("nature") and that system doesn't care about my "morals" or lack thereof.

Sorry for the weird pretentious rambling. My response is that humans are part of nature, not apart from it, that nature has no morals or good or bad. Morals are just this weird thing human brains do to cooperate as individual members of a species to increase our fitness and individually to feel better or worse. I care about other humans because I care about them. I don't care about crabs because I don't care about them. They are two separate, non-intersecting roads in my brain. I don't mind if you think I'm a heartless psycho for articulating it this way, in fact the main drawback of this way of mental mapping is literally the social stigma of being considered heartless and cruel, which is why I am less likely to phrase it this way in IRL conversation. But I feel nothing when I crush a house fly (rather, I feel great satisfaction at getting rid of such a nuisance, and I think most others would feel the same), and feel nothing when I boil a crab alive except the pleasant anticipation of a delicious meal.