Gender Reversal Scary?

I found it very interesting during the LRRH discussion about the critics many of the guys in the class became very uncomfortable when the concept of gender reversal became the topic of conversation. So much so that one guy even dropped the class. Why is it that women can so easily accept the idea of a gender reversal in a story or fairy tale whereas men have such an issue with the idea? I think fairy tales themselves have something to do with it, we are brought up on these fairy tales that instill a message that men are strong and capable and women are domestic, naive, and weak. This training continues on throughout a young males life, "men are stronger than girls," "men don't cry, or show emotions" etc. This installment of ideas has gone on their whole lives so then to have someone suggest a role reversal, a loss of the masculinity they are told to always have, it's just unacceptable to them. Maybe some of them even connect with the wolf as a symbol of masculinity strong, capable, never shows any emotions, so then to have him turned into a woman, his mouth into a vagina? Unacceptable.