Ah yes, the anti-vegan. Nearly as annoying as the vegan.

I have the same advice for you as I have for vegans: let people eat what they want to eat, mind your business, and keep your preferences to yourself unless you’re asked.

That said there is some irony here because you’re framing this as unreasonable, but we do this all the time with other humans. As an outsider you should treat members of a group differently than they treat each other - unless you’re saying white people should be allowed to drop N bombs lol