Much as the article makes good points, I find it difficult to believe that the list of meats banned by kosher and halal matches the top allergies and disease risk factors as well as it does without some intent. Pork was, until very recently, the greatest risk for parasitic infection, insects in a similar spot. Shellfish are the top meat allergy, by a whole lot. Most of the rest of the rules about preparation amount to good practices for ensuring cleanliness or at least reasonable preservation and parasite prevention. There are exceptions, I can’t think of a practical reason for not allowing meat and dairy to come into contact, but the vast majority would have kept people healthier.

Whether it originated from an us vs them ideology or not, there were practical benefits for a population that made those choices that would have reinforced it in pre-modern times.