I don’t begrudge anyone who simply can’t bring himself to eat animals; de gustibus and all that.
But some of us do consider vegan arguments and find them unpersuasive as arguments. Rhys Southan has written about the “vegan shuffle,” in which vegans pursue one line of ethical argument, that animals have rights, until the point at which their opponent points to a hole in it. Perhaps the non-vegan will notice that a strict adherence to animal rights would require the abolition of agricultural techniques that the current vegan diet relies on, since these kill some animals (pests, animals caught in threshing machines, etc.) and steal and destroy the ecosystems on which yet more animals depend. The vegan will then shuffle toward an argument that they are simply interested in harm reduction; they don’t want animal rights exactly, but only to be better.
But point out that there are other strategies that could reduce animal suffering while still allowing humans to eat meat — changes in slaughtering techniques, etc. — and vegans will “shuffle” back toward the animal-rights argument to show why this by itself would not be a sufficient moral response. Or perhaps you could propose a wilder solution that ends more harm than veganism by radically shifting the human diet to the consumption of bivalves, which do not feel pain. This too causes the shuffle back to an animal-rights argument.
