Behaving well is costly and it's not likely done if there are no social rewards for it. If you belong to a negatively stereotyped group like men, what's the reason to try to act dissimilarly to the stereotypes if 1) by default that stereotype is true but 2) people can act otherwise of they want to. If the general publics reaction to these two groups is the same, why would anyone try to act counter stereotypically (think men being violent sex obsessed cheating pigs) as long as it's legal?