Humans have been eating meat for millions of years. Animals eat millions of other animals everyday. Yet some vegetarians and the vegans believe than it is an act of cruelty for a human to eat meat.
The decline of traditional morality does not create a vacuum, rather, it is simply replaced by another morality. The biblical notion that nature is here for us to conquer and subdue for human fulfillment, a belief that contributed to the success of the Western world, is being replaced by the notion that nature must be protected. The biblical notion that man is special and has rights because he was made in God's image is being replaced with the idea man is not special and nothing places him above the animal kingdom in terms of moral worth. This is why we live in a world where one can refuse to drink beer brewed with honey in protest that it was harvested from bees, while at the same time have no regard for the rights and well being of a human fetus.