I have had my life saved at least a half dozen times by helmets. Here is one after a pretty similar crash I had at 100-110mph on the track. Lots of broken bones, but no head injury.
When I lived in Florida, I was unfortunate enough to come upon several crashes just after they happened and witnessed what happens when a human head impacts the pavement, or a car. I also had a good friend die two years ago 1/2 mile from my house because he was a moron, riding drunk, without a helmet.
However, I fully oppose helmet laws, seat belt laws, and every other law that "protects us from ourselves."