Harris' point is correct about islamm and judaism's reasons for rejecting pork, but do not make any sense when talking about Hinduism's ban on the eating of beef. Firstly, Hindusim is mostly against the eating of any animal because it believes in reincarnation into different animals, so if you eating an animal you may be eating your great grand mother. Next, the cow is useful both as a pack animal and as a provider of milk, so must be preserved.
Maybe just reinforcement of the 'don't eat' taboo...don't know.