Because then you look a fool to onlookers as well. People who "lose it" in public are looked askance, whether they have cause to lose it or not. They place themselves on the same level as the one who caused the injury.
It's like looking at a cat fight. Most onlookers don't care who started it, they are too busy enjoying the show.
Hopefully Marcie was not dressed when she said that. Otherwise, there are huge chances that onlookers would see CDers as being unstable and having volatile tempers.