I understand your point, but if we take them away, then people will start to think it's okay to take away other weapons, saying things like: "Well, nuclear bombs are dangerous too, so are atomic bombs, so are hydrogen bombs, so are missiles, so is the smell of my gym socks...ect."
Also, larger bombs may sometimes have more of an after effect than cluster bombs do. Such as left over radiation, making it so nobody can even be in the near for years.
But, there isn't really much point in arguing with this, it was only for a school project.