Imagine this: the female model takes a long time to make, with the tit extruding and cloth shading, player rendering, etc. Now, imagine a male model. the models are different, so you cannot just copy 'n' paste a bunch of code pieces. And the shading... you would have a totally different story.
Now imagine all the TF2 Player models. Making one is hard, making 2 is even harder, making more than 2 is B.S. Understand, MegaScientifical?
<i don't know if you did this on purpose, but Scientifical isn't a real word. Maybe you meant 'Scientific'>