Good catch. Its interesting that the gender-neutrality comes only in the "Sex" and "Relationships" sections, and that the only female "I am <famous person>" comes in "Sex" for "I am Madonna."
Are you referring to the phrase, "clothes make the man" (which I've always taken to be relatively gender-neutral, since it's about how your presentation affects how others treat you / see you), or to the references to wearing pants/slacks?
Definitely the examples, not the phrase.
It reflected the state of things in 1996.
Actually, I was an undergraduate in 1993 (when this was first written) and I can assure you that there did exist women who did geeky stuff, were in STEM fields, etc. In fact, I did research for a professor then who was precisely such a woman. I don't want to overstate this, but little things like these add up to a perception that things were a way that wasn't really the case.
Despite this, I had my geek code proudly displayed on my website for years! :) (d- for appearance, although less so these days.)