"Sissy" may very well be an appropriate word to describe some on the tg continuum, but not so much applicable for CD'ers who wish to present fully as women or those who identify as TG/TS (this girl included, it's the last word I'd even think of using for myself).
As for the concept of "sissifying" the male muggles of the world, I'd have nothing of it. Face it, the differences between the genders is part of what makes us what we are. Evolution of fashion trends is one thing, conversion of others who may not necessarily gravitate towards such expression is yet another. Blurring gender appearances (ie-appearing as a "sissified" male") isn't likely to change anything in and of itself, especially for anyone who wasn't already predisposed to being gender variant in the first place.
