Really! Consider this analogy. Lets say you have a 12 inch long metal spike attached to the middle of your car's steering wheel pointed at your heart. Will you drive slower and take less risk with the spike then you would without the spike? I rest my case.
Reality is they have done speed tests at multiple ski areas. I believe the skier speed with helmets on average is something like 4 MPH faster than skiers without helmets. Snowboarders also go slower than skiers. Kinetic energy your body caries increases non-linear with increased in speed. 4 MPH speed increase can be a huge increase in kinetic energy and the difference between life and death.
As an EMT blunt force trauma to chest is a real killer. Ribs have a tendency to puncture lungs. The pericardium sac around the heart can fill up with blood from only a slight bleed from the heart. The blood builds up pressure in the pericardium sac and pushes on the heart causing a decrease in difference between the systolic and diastolic blood pressure readings (narrowing). Your spleen in the upper left quadrant of the abdomen may be ruptured. Without emergency treatment, a ruptured spleen can cause life-threatening internal bleeding. Fractured pelvis may result in severe internal bleeding. There are a lot of ways to die without a head injury.
