The whole point of Rachel's Challenge was to teach students to use kindness to make others feel better and hopefully avert tragedies (including suicide). Being friendly might work to stop the occaisional angry outcast type, but it will not work on the real maniacs.
IMO, "being nice" can backfire. I certainly was never angry, or picked on during those years. However, I can certainly relate to depression, feeling invisible, and outcast.
The bright shiny happy popular people who were nice and friendly to you in passing in the hall, or next to you in class were worse than being ignored, when after a brief surge of hope, you realized it didn't really mean anything other than that you're a generic sounding board for their need to be nice.
After that realization, the bright bubbly, camp-counselor type of pretty girl who'd chat you up was like nails on a blackboard, because she was no more a friend or a potential love interest than another girl who ignored you completely. It's like being a homeless third-world kid given a five minute tour of an American mansion decorated for Christmas, then dumped back into your slum.