Why do people get repulsed when they see something gorey?

Like when they guts, dead rotting carces/bodies, dismemberment, decapitation, disembowlments, cannibalism and all that other stuff. Some people even get offended by some of it, and I really don't see why. I mean human and animal meat are the same thing to me, we pretty much have gorey things going on almost everyday(like cutting up meat for dinner etc.), I mean meat is meat no matter were it came from. I also don't see why people lose thier appitites either when watching these kind of things, I could eat a rare steak while looking at things like that.