And this sums it. The two sides of the helmet debate are so heavily entrenched, neither is for shifting. You are perfectly entitled to your opinion, and your opinion is worth no less, nor no more than that of anyone else. I assume (apologies if this is not the case) that you don't wear a helmet for your own reasons. I'm not in favour of compulsion so this is entirely your choice.
It's something i've never really had an opinion on one way or t'other before my accident last week. Cycling is very safe as you say. In over 20 years of cycling this was the first major accident i've had. I've probably fallen or tripped over as a pedestrian more times in that period and hit the ground quite hard when tackled at football and as you say, no-one would think of wearing a helmet for these activities. But i've never travelled at 35mph as a pedestrian or footballer before, nor been cartwheeled into the road several times before coming to a standstill. Yes, i know my helmet would not have been tested under these conditions, but i am adamant my injuries would have been much more serious were it not for my helmet. I think it would be pretty difficult to dispute that, so in my example, yes it might not be perfect and the design many focus on fashion as much as safety, but i am of the opinion that helmets offer "some" protection which in some cases may help to reduce injuries. I'm also prepared to accept that in some cases they may not.