I really don’t understand their position.

Cats cannot make a moral choice so what are these folks going to do when they see their “vegan” cat take down a bird or a mouse?

The fact that domesticated cats are notorious hunters really does make this whole thing pretty fucking funny tbh.

When is science ever “conclusive”?

That very concept is anti-science.

Nowadays “the science is inconclusive” is used to weasel out of corners that grifters paint themselves into.

Scientific consensus now there’s a concept worth understanding and putting forth in arguments such as this one.