If I'd read this thread a few days ago, I would have immediately said "yeah there's nothing cruel at all about that! It would have gone down the same way, what's the big deal?"
Then... the other night I watched Jurassic Park and I saw a live cow being lowered to its death to be eaten by a dinosaur and now... omfg. I think what makes it cruel is the human element to it. In the wild it's natural, but when a human who should have a conscience can willingly capture an animal and feed it to another... there's something messed up about that.