> Almost No one would purposely harm an intelligent animal

Except for the fact that human beings have been purposely harming intelligent animals for food for millenia.

Unfortunately, there are plenty of people who eat chimpanzees and gorillas as bushmeat, even while appreciating their intelligence. There's no contradiction there. Humans are predators--don't underestimate our capacity to dissociate and follow our predator instincts. In fact, forget the whole predator angle--don't underestimate our capacity to dissociate. That ability isn't inherently bad; it's one of the things that makes us human, and is a prerequisite for making choices in the first place.

>Almost No one would purposely harm an intelligent animal

Thought experiment: is it ethical to eat animals that have been genetically engineered to be braindead?

I think genetically engineering animals to be braindead is itself the unethical action. If we're willing to sacrifice efficiency we could emulate what animals go through in the wild. They live a life full of socializing and emotions and then slaughtered for meat at the end.

Is it ethical to genetically engineer animals (e.g. people) to be braindead?

I've known some (otherwise) vegetarians that ate bivalves, kinds of the same thing.

I'm not sure if this is a useful thought experiment.

Why not? Animal welfare is a primary reason why some people don't eat meat. Making them braindead should alleviate the concern for those people, but I have a feeling that the same people would be against it.

The weird part might be in the rest of the quoted sentence where they don't care what other people eat.

I am not sure if that is even weird tbh. Maybe I am an outlier, but I know a lot of vegetarians and can't think of a single time where they have commented about someone eating meat.

I don't think vegetarians are usually the ones commenting, there's a reason vegans get a lot of flak on the internet. I've also never heard vegetarians commenting on anyone's dietary choices.