Thats just it dude. As my hobby is armorsmithing I can tell you EXACTLY what helmets are for. Protection. The problem is that when something is made like shit and with shit it tends to do a poor job protecting. Your better off wearing a different type of helmet for bikes. I did research on this not to long ago and there is no real evidence that they do more good than bad. There is however evidence that if people used their brains (as you stated in your post) that they would not need helmets. Because them and the people in cars would drive smart and be more cautious.

I say forget about the damn law and lets spend time on something more important. Like oh say EDUCATION.