No one likes this role. However, the safety of everyone is at stake. So, pleeeeeese, when you see something wrong, especially if it is done repetitively, say something. If you are uncomfortable saying something or it doesn't seem to be doing any good, let the staff know and we will ask for improvement. It is common to see people involved in sports wearing head protection.
Football players wear helmets.
Rock climbers wear helmets. River rafters wear helmets. Hockey players wear helmets. All for good reason - each sport presents a risk of head injury. Bicycling presents similar hazards and requires similar precautions.