I think this thread got off track. Whether or not humans evolved to eat meat is irrelevant. Many of us choose to because it gives us pleasure. I'm not convinced that eating meat is slowly killing me, but if it was I would not stop. BBQ is too good to deprive myself of, and I'll damn well trade a few years of my life to enjoy the food I eat for the rest of them.
The question the OP raised is not "Are humans designed to eat meat?" but rather, "Is it moral to raise and slaughter animals for sustinence?"