At first I was completely agreeing with you and found parent's sentiment misguided. But, then I thought what if we took this to an extreme and generalized about humans? Human violence isn't always uniformly distributed amongst the races, but we try not to jump to conclusions about supposed racial genetic predispositions. I think the dog deserves the benefit of the doubt is what I'm saying. But that's also not accounting that some dogs have been bred for violence. So I guess you are right in some ways and wrong in others.