Allister, I think you need to reference motor racing with this. The simple (petulant) act of throwing a racing helmet on the ground will likely get it banned from further use by race stewards. Helmets involved in a race/rally accident automatically have their straps cut if a steward or race official gets to them first. You must be joking or trolling to say that you would expect a helmet, at any price, to survive 5 or more crashes.

I haven't seen a race or motor cycle helmet for a long time (I gave up motorcycles around 30 years ago and rally driving 20 years ago, although I was still in motor sport administration 10 years ago), but the principles for cycling helmets and helmets used in those sports are little different when it comes to controlled deceleration of the skull. They, too, have a cell-foam layer. The hard outer on motorcycle/racing helmets does play a role in terms of preventing penetration. But then again, maybe helmets should have been banned from motor sport when Ayrton Senna was killed by a component penetrating his helmet. Quite obviously they are ineffective

By the way, thicker pads (as offered with cheap bike helmets to help them "fit" better) apparently interfere with the controlled deceleration of the skull the helmets are supposed to aid. Thinner, apparently, is better.

I'm not advocating one way or the other on compulsory use. Like Allister, I am required by law to wear one when riding in public areas. I wouldn't consider riding otherwise law or not, such as in Europe last year. It's just a discussion about helmet design in this case.