Because more people are mind limited. Because someone told them to harm is ok, that suffering of someone else (yes, someone, because animals are someone, not something) doesn't matter. I've been vegetarian for 15 years and I don't regret it for a second! This is the right choise, this is a way to live, not a habbit or thinking. Leonardo da Vinchi said it long ago: "The day will come, when men such us I will look upon the murder of animals as they look upon the murder of men."
Exactly, I'm slowly working my way towards becoming a vegetarian, but there are people using "Plants like living too." as an argument. I don't get why people have to get angry at others for what they choose to eat. Not like you're taking drugs. And you CAN live without meat. Two of my cousins have been vegetarians their whole lives, and they don't have any major problems.
One of my teachers became vegetarian because she didn't like the taste of meat, not because she didn't support the idea of hunting. Its stupid on when you tell some people you are vegetarian they baw about you being all peta and shit.