Ignorance.

She sits quietly in her seat, staring out the window. People passing by look at her differently. Some think she is crazy, perhaps a victim of schizophrenia; others ignore her. It is because of these ignorant people she has become withdrawn. They have forced her to make a choice: be outspoken and give to the world, be ignorant like them, or just go and take away from this place. 

So now she sits quietly in her seat, staring out the window, out at all the ignorant people.