As I already said in a thread about Sex, it might be linked with the fact that we subconsciously think of women as inferior, which can be explained by many reasons. For example, we all learn about feminists and the fact that women WERE considered inferior until relatively recently, and that they didn't have as many rights as men. This may cause us to subconsciously think about the "inferiority" of women without truly believing it (that would be sexist and silly). There's also the fact that men are more aggressive and virile in nature than women, which is considered superior. Women are generally more submissive, therefore telling our subconscious that they are inferior. No offense meant to women.
There's also the fact that women in men's clothing is considered normal, and more aggressive and direct women are more often considered sexy than tomboy-ish. Women are naturally considered "cute" and "pretty", or at least stereotypically. Hairy men are NOT cute, nor are they pretty. At least not usually. They can be virile, manly, gentlemen, sexy, but cute is exclusive to women.
One more thing. As a child, I'm sure that you've considered girls to be inferior because they were weaker, because they didn't play video games well, because they didn't like cars, or something similar (if you're a guy). I'm talking about stereotypes here, so this may or may not apply to you. Anyways, kids have a very limited logic and they learn the basics of living using this logic. When you strongly believe that girls are weaker and therefore inferior for so much time, you eventually keep thinking about it subconsciously, while knowing that women are as valuable as men.
There must be a lot of other reasons, but I feel that the three I explained in the previous paragraphs may be part of the fact that some men like to be embarrassed by wearing women's clothing and act like a little girl.
No offense meant to women, but that's my opinion. I don't believe in the inferiority of women, or at least not consciously, and anyone who does is mistaken, sick, childish, immature or ignorant, but our subconscious can contradict what we truly believe.