EDIT: Don’t bother reporting people criticizing others for not wearing a helmet. It’s not victim blaming, just like criticizing someone for not wearing a seatbelt isn’t victim blaming.
Wear your helmets people: Of course nobody deserves to get hit by a car but the reality is people are getting hit by cars.
You might be missing practical experience of falling off a bike. Happened to me. Speed makes a difference in any situation where the bike falls over or the rider falls off the bike. why? because speed is a major source of kinetic energy when colliding with the ground (the other source is the difference in height). You listed 6 different possible causes for falling off a bike, and all of them result in more energetic falls if the bike is going fast.
Are we concerned about an initial impact, the probable falling-off that occurs afterwards, or both? I personally care mostly about the reasons for initial impacts because without colliding with anything, falling off a bike becomes much less frequent and less severe.
Even the circumstance of falling off a bike without a collision with anything else is improved for everyone by good infrastructure: grass-lined paths, telephone poles placed far away, a buffer between oncoming bike path lanes, full separatiom from cars, etc… All those infrastructure changes benefit everyone, irrespective of whether a particular rider falls while wearing a helmet or not.
This fixation on helmets is a case of missing the forest for the trees.
if you change the perspective like that, yeah, safer bike infrastructure is very important.