My reason is along the lines of what Risa said, which is that since I can survive and eat a healthy diet without killing a living being, I don't eat meat. It is partially a religious reason as well, because I believe if it's possible to survive without hurting another, human or animal, it's my responsibility to do so. I find much of the meat industry cruel and wasteful, in that many animals are killed for certain parts of them for consumption, and the rest is thrown away. In Tibet, for instance, food is scarce, and the Tibetan Buddhists are very much against killing of any kind, however one of the few food sources available to them is yak meat. As a result, they do eat yak, but they don't waste any of the animal, they use all the meat, the skin, even the bones so that nothing goes to waste (many other indigenous cultures do this as well, but Tibet was the first place that came to mind). I have a profound respect for that, and since I do have a multitude of non-meat sources of food available to me, I eat those.