Oh dear Lord.
Dudes, this was the main point behind my project on parkour and women (which I am wrapping up as we speak). From my research, the misconceptions arise that women think they will get hurt, it is not "dainty", it's different, and it's a way that their bodies are not socially conditioned to move.
That being said, there is no reason at all in this world that women cannot do parkour. None.
Also, this fact that guys want to meet traceuses because they are "hot" is another thing that discourages girls. If girls think that they are going to be hit on whenever they train (or because they train), then that makes them hesitant to do so, because they want to train for their own reasons and feel "safe" doing so.
It is nice to appreciate the other sex in training, but the way to do so is to appreciate people as individuals, not as groups.
And I apologize if this came across as angry, not my intention at all.
I appreciate all you guys and girls, and I'm glad to have a community like this to discuss these types of issues. And if you want to discuss this more, I'd be happy to do so; you can pm or add me on facebook