Because we be BAD.
Well if it is in the fabric of the human mind, then why do doves exist to give advice at all? Please, hawks win because "the world is governed by the aggessive use of force" as Rush would say.
If there are any aggressors at all, then there have to be hawkish people to stop them because dovish people are, well,....dovish. By the author's own admission, no one listens to doves, so why is dialogue even an option?