Why is that so?

Why is that so? Seeing my dear friend suffering and i cant help or do a thing. Why do guys like to jump into a new relationship when the previous one is still hanging in the mid air? Seeing her being so troubled, I told her to leave thats the only thing i can help not to feel hurt further. I know she is hurt, tired and she feels that she is just a life bouy. I really have got no idea how to console her. She said whenever she feels like talking, he says he's tired and do not wish to talk anymore. She had got no idea why she is being entangled into such situation. And it's usually the guy who dont want to be firm and make a decision or outcome to it, they just like to hide, or drag it along. In the end we're left the ones suffering. Indecisive. She is once like me, believe, understands, trust, loving yet the nice ones ended up getting hurt.