Religion: Why did the pig become so unpopular?

Recently, a friend alerted me to an item of junk called "Clean Conservatives and Filthy Liberals" that I can no longer find online. It may have been a gag, or perhaps a riposte to some other junk, like this ("From the Iszatso? dept: Thoughts from Sharon Begley on "liberal" vs. "conservative" brains ")

Anyway, gag or not, it raised some interesting questions for me, one of which is how some animals come to be forbidden food. Obviously, most devout people are just going to follow their religion's guidance in these matters, but sometimes there is more to the story. I am thinking of the interesting case of the pig in the Middle East.

Years ago, an author pointed out in a book on economics that pigs differ from most animals kept anciently in those regions because they are not multipurpose. I quickly made a list of factors that he mentioned, plus a few others:

1. Pigs compete directly with humans for food. (Most agricultural animals do not compete directly with humans for food, because they can eat things humans cannot.)

2. Pigs drink a lot of water. That is inconvenient in a dry environment.

3. Pigs cannot be milked.

4. You cannot ride a pig.

5. Pigs cannot be used as pack animals.

6. Pigs do not pull carts.

7. Pig skin is useful as leather, but it is not a fleece.

8. Stampeding pigs may trample their keepers. (You’re lucky if they just run off a cliff in that case, as in a famous incident in the New Testament.)

9. Pigs can give humans diseases like “swine flu.”

10. It is difficult to develop a relationship with an adult pig, unlike say, a horse or donkey.

So, if people who live in a semi-desert environment are not going to eat an animal for religious reasons, to demonstrate their faith, it may as well be the poor old pig. Perhaps he isn't quite as bad as his reputation, but he is too ecologically expensive for many environments.