I know when we're being rational (and by "we" I mean people in general) we can all say that there are other options, that we don't have to be violent, etc etc. But how many of us actually do that when we're pushed? If the people we love are hurt, most people react emotionally, don't they? And vampires, my kind anyway. We are emotion. Everything we feel is more intense than a human. When we hurt we really really really hurt. All our instincts are to lash out and hurt back.
People just seem to get so much angrier with us when we point this out or when we get protective. Is it because they know that not only cold we follow through with it, but there's not really anything anyone could do to stop us?