Yep, I kinda do - Because falls not related to a car hitting you won't affect your head, and if you do get hit by a car on a bike, that little eggshell won't do much to help you when the rest of your body gets smeared across the pavement like so much squirrel.
If you are not smeared across the pavement but only hit hard enough to be thrown a few meters the helmet will protect you and avoid the your scull cracks open if your skull is first when you hit the curb. (or a signpost or anything else that is not flat road)
Safe bicycle infrastructure promotes faster speeds and more confidence and feeling of ownership of the road by cyclists. These are all components that speak FOR the usage of helmets. Speeds on the danish bicycle lanes are often high enough that if you get graced by another cyclist going past you you will fall (and the curb will be very close)
In Denmark, if you get hit by a car it is by default the drivers fault - it is also an integral part of drivers education to be very much aware of cyclist when making turns - especially right turns.
I do not think helmets should be mandatory, but they should be heavily promoted and maybe even subsidized to make them more easily available. Laws could also be passed to ensure that every bike has to come with a free helmet bundled. "Use it if you like, but we are obligated to give it to you. And please read this flyer on bike safety."
Its like insurance - you don't need it until you do - and at that time it is too late to buy it (or in the case of helmets - put them on)