Excepting, of course, the fact that the human body needs meat. If you go Vegan, you need to take supplements. And if you do, well, good for you. Regardless, the human body is designed for both the consumption of animal and plant matter. We're omnivores.
Yes, it's sad that animals die so we can consume their flesh, but that's life. Lions kill and eat their prey. Bears do, too. And they don't give a damn about the suffering of the animal they kill. Some wildcats suffocate their prey, which is a slow, agonizing death.
Some animals don't even wait for their prey to die before they begin eating.
Seriously, the world is a cruel place. And honestly, compared to other animals, humans as a whole (outside of certain situations which PETArds love to blow up out of proportion) tend to be quite merciful to their prey, aiming for quick, painless deaths.
That being said, we could be standing to eat less meat.