I don't think anyone would argue that frames in America with dropped top tube (not to be confused with a dropped tube top ;-)) are historically viewed by the general public as girls' bikes. The French apparently do not share this practice, because their term "mixte", which I believe has been around a long time, means "mixed-use" or "multi-purpose", rather than "girls' bike". I think the wide acceptance of the term "mixte" itself argues in support of the gender-neutral theory, at least in France. I've also heard the term "step-through" as an English attempt to overcome the perception of these as girls' bikes.
Perception is reality, sometimes, and I don't think I will ever be able to see a mixte parked on the street without thinking of it as a female bike. I keep thinking that if I had bought one of these for my wife back when, instead of following the then popular opinion against them, perhaps she would have done more riding and enjoyed it better.
If I wanted to ride one of these myself, just because they are cool, or because they are easier to mount and dismount, I would do so and not worry about the opinions of others. Maybe not a pink one, though.
John Hurley
Austin, Texas, USA