I’m not completely sure why I like the Chinese character for vegetarian, 吃素, pronounced chī sù. It implies a choice, instead of an identity. That is also exactly how it applies to modern Buddhist culture, as a choice. Of all of the Buddhists I have met it China, only about half of them impose this dietary restriction on themselves. Yes the Buddhist religion recommends that followers stick to a vegetarian diet, but never that not doing so would result in some catastrophic trip to the Buddhist equivalent of hell (which for the record does not totally exist).
The reason that Buddhists do not eat meat is relatively simple: reincarnation.
Humans are one of the most unfortunate animals on the planet for their capacity for passion and love also results in susceptibility to discontent, unhappiness and suffering. But, if a person can commit to serving Buddha, chanting holy mantras, performing rituals and overall bettering him or herself as a person, they will be given another chance a happier life, or even a complete break from it. These multiple chances for those who are good is a concept called reincarnation, and it is one of the most well known Buddhist concepts today. Someone’s soul can be reborn, not necessarily as a human but as another animal, and maybe back to human again; this cycle continues, repeating birth and death. Though the bettering and cultivating of ones soul, however, the cycle can actually be broken and they can reach Enlightenment.
This means that Buddhists view the living, creatures are seen not as animals or humans but as beings equally deserving of life.
So as equivalent beings, if one being has the ability to choose not to eat a fellow being, he or she should not do so and instead stick to a diet; hence vegetarianism.
Humans are a species on earth that have the unique ability and the means to choose what it is they eat, without needing to hunt or graze or scavenge. We also have the ability to live solely on vegetables, without any meat consumption; in the Buddhist mind, without having to bite, chew, swallow and digest an equal being or soul.
But one interesting thing about the Buddhist religion as a whole is that a practice like vegetarianism will never be preached to you. While in China, I never once saw glances from monks in the Peking University dining hall when everyone around them had meat on their plates. Nor was anyone questioned for ordering meat dishes at a restaurant next to a Tibetan monastery. If you want to eat vegetarian you can, but if not there’s no problem, which is one of the reasons I believe Buddhism is so widely accepted through out China.