Personally, I've always seen cow's milk as the quintessential drink of Western Christendom: something that Germans, Scots, Englishmen, Scandinavians, Celts (from the Hebrides all the way to Navarre and Galicia), and provincial Frenchmen consume, but that's all but unknown among foreigners -- including the predatory, Viking-descended aristocracies in London and, especially, Paris. (The English upper class proverbially never trusted an adult who drank milk; the French upper class hardly even remembered that it existed, except as a precursor to cheese.)

My theory is that those who hate milk see it in the same way as I do, but don't share my fondness for Western Christendom. The old-money "Northeastern establishment" in the United States never quite forgave God for how His Book is fine with slavery; Jews and Germans always did feud, but these days the Jews have very good reason to be frightened when they hear talk of traditional voelkisch German-ness (which in any case never did like them); eastern and southern peoples, not all of whom can consume milk in the first place, might reasonably regard milk as a symbol of a society that was as rich as it was xenophobic. And people born into the old Western order but seeking to escape it -- including most Americans, to some extent or other -- might want to escape its symbols, too.

Does this sound about right, or are there other reasons for disliking milk? I can understand personally not drinking it, if you don't have mature lactose tolerance; I can see excellent reasons for disliking industrial dairying with battery farms of miserable, inbred, inadvertently-cannibal cows (I don't touch milk unless it's organic and from humanely-raised cows); but if it isn't for the reasons above, I don't know why people dislike -- indeed, passionately shun and repudiate -- the very idea of drinking milk.