I definitely don't have the answer to this one, but my karate teacher used to say the same thing almost exactly. He said it IS your responsibility to try and 'discourage' the attacker from ever assaulting someone again. Or at least think twice.
In practice I don't think that this is a plausible theory. In my opinion, a thug is a thug and a beatin' is just going to piss him off more, unless you cripple him, or kill him....not very aiki