Gender roles are mainly a construction of society. Those constructs persist because the population at large maintains those constructs. (If we didn't care for the constructs in the first place, we would have gotten rid of it already.) Crossdressers compose a threat to that construct, and demeaning the activity is an activity which helps to maintain the construct of distinct gender roles. The thing is, gender roles for women have become more and more plastic, because assuming a more masculine identity is neither embarassing (grabbing more power is never embarassing), and also that women have in general historically have been recognized as victims, and that enforcing old structures of dominant-submissive male female relationships is considered bad. Much of the time, when documentaries cover transgendered people transitioning, they often focus on female to male, for the reason of creating sympathy, because the public is much more at ease with it. Male gender roles, however are strongly as enforced as ever. The strong emergence of the male gay community, and the feminist movement, has created a surge in the need for male heterosexual men to stake out their identity against such "threats", since masculinity is largely defined by homophobia and objectification of women, at least historically. As a result, male objection to crossdressing can be quite strong, especially because of the misperception that gay men are really "transgender"; the perception that a man liking another man is impossible; only feminine or "womanly" men could like other men. (This stereotype is not lost on the gay community; the bear movement is at least part of a counter to this perception.) In addition, some of feminism objects to male to female crossdressing, because it can be percieved as a threat to femininity, men trying "to take" what women have worked so hard to earn. Then there's also the risk of being "trapped" by a transgender person, either a man falling for a crossdresser, or even a lesbian falling for a crossdresser, only to discover to their dismay, they have been made inadvertently, gay/straight (respectively). That then arouses a sense of self-doubt and perhaps self-disgust because of aforementioned gender role definitions, and that may be translated into fear, hate and even violence, targeted at the person or group.