It has less to do with power and more to do with role fulfillment. If one views the male as an avatar of responsibility, hard-work, etc., as per the traditional Judeo-Christian ethic, one will see that male as "shirking" his "natural" role as a man and provider to "retreat" to the "unnatural" role of the feminine nurturer. It's only because we associate biological sex with propensity toward and proficiency in a given role. Goes for ftm too.
In this sense, I'm more inclined to agree with Annabelle's statement that it symbolizes some corruption of the natural order to those who delusionally believe themselves to understand that natural order.
These types of analyses submit themselves best to symbolic interactionism, begin at the micro-level, and determine the structure of the phenomenon piece-wise.
