I think it has something to do with the fact that many (not all) MtFs are heterosexual men who dress as women, and since crossdressing is often seen as queer, they're worried that they'll be seen as gay. On the other side, many (but not all) of us FtMs started out thinking we were lesbians and got comfortable with that fact before realizing we were transmasculine. I think that's just one of the reasons. Another could be that guys tend to be less high strung the girls. :winkp:
But I think the biggest reason why we don't seem to fret over our sexual orientations the same way many MtFs do is because we are a minority within a minority within a minority, and as such we've learned that labels only serve to separate us further.
