Are we actually going to use terms like "masculine" and "feminine" at face value, without adding the caveats that should be obvious to all by the 21st century? Masculinity and feminity are social constructs, which reflect the expectation society has toward men and women respectively. They do not actually have an inherent link to a person's sex.
I thought that the absurd idea than masculinity and feminity are social constructs was more typical of the mid 20th centuries and has long since been rejected. See this case, for example
I think you miss the point. The gender theory doesn't mean to say human beings can be toyed around and shaped the way that most fits some mad psychiatrist. Any attempt to force an identity on someone can result in tragedies like Reimer's - in fact, whether or not he had a Y chromosome matters little to the moral of the story. The whole point of gender studies is precisely to deconstruct the idea that people
are male or female and therefore should
act a certain way, and let everyone free to express themselves however they feel.