Why Can't Girls Like Science Fiction?

I Love Science Fiction. I won't lie. Now most girls my age would never admit that. In order to be seen as your steriotypical "girl" you must love three things: Clothes, Makeup, and Boys. 

Unfourtunatley, for me, its: Starships, Blowups, and Robots. Now don't get me wrong. I'm no Tom Boy. I like to dress up in pink and purple as much as the next girl. I wear makeup, comb my hair, giggle, gossip (well, not to much of that...) and straighten up when a cute boy walks by. But at  home, time to put on my Star Trek: Voyager t-shirt, grab my Stuffed Turtle and a Grape Popsicle and curl up in front of the "Spike" and "Sci-fi" channels. When I was a bit younger, the thought of anyone knowing I liked Science Fiction horrifyed me. I kept it my best hid secret. Now I'm a bit more loosed lipped about it. I'm even attending my first convention this august! Now I wonder why it is not popular for a girl to admit to loving Sci-fi? Why is it that girls are expected to play with baby dolls and barbies, while guys get to play with action figures and remote control cars? Some times I feel like the only girl on the planet who likes these shows!  Why is it that when someone says "Nerd" shows like Star Trek, Star Wars, and Doctor Who come to mind? These are things I have always wondered...If you have any ideas, feel free to post a comment...