Studies show that 100% of hijackers who crash planes into large buildings are Arab. Does that mean we have policies that Arabs don't sit in any airline seat?
Studies show that a substantial percentage of non-initimate violent crime is committed by men under 30. Does that mean we have policies that mandate curfews for that group?
Studies show that a substantial percentage of muling drugs up I95 is done by young black men. Does that mean our police pull over every car driven by young black men on I95, even though they're breaking no traffic law?
Each of the hypothetical actions above could arguably benefit society. So what? Unless we want to conduct a constitutionally disasterous experiment that'll make what our grandparents did to Japanese Americans during WWII look benevolent, we need to remind ourselves of the proper applicability of statistics-based reasoning. There are things we don't get to do, regardless of rationales we can cook up to justify the actions. Discrimination such as those airlines are demonstrating is beyond the pale constitutionally (if done in America -- I don't know enough about Aus/NZ to comment on their legal context), it's morally contemptible, and if it ever gets turned into a generalized policy of discrimination against men because they're men ... a social catastrophe exceeding anything else ever experienced by western civilization is likely.