I tie it to my bag. I've seen ones that fold to a size of a banana. If someone breaks the chain then they take my bike, the helmet is the least of my concerns.

The idea that use would be discouraged because of that is ridiculous when you consider the alternative: cars or public transport. Both are terrible options. Parking, traffic, etc.

I'm 47 and had a crash recently. How does my age have to do anything if someone suddenly jumps in my lane or a car runs into me?

If anything my healthcare bill will be higher.