And, we're off...
I'm generally against more laws for the sake of it and certainly laws that only protect us from ourselves. There's a difference between the wisdom of wearing gear and the compulsion to do so.
Not wearing gear or a lid only harms the rider, so why legislate? Maybe some folk want to ride without a lid, not because they're stupid and think it's safe, but because it's dangerous. Fair play if that floats your boat.
I would personally wear a lid most of the time even if it wasnt required - certainly needed for stone and wasp protection, never mind an off. I think it's probably a wise thing to do.
But I would also support this guys right to ride without one if he chooses. If his enjoyment of riding without a lid outweighed the increased risk then that's entirely up to him. It's his head, not mine.
I know people who think I'm mad to ride a bike because they think it's too dangerous. Personally, the enjoyment outweighs the risk (which they have overestimated anyway). It's exactly the same thing, just a different degree and perception of risk.
I used to go rock climbing when I was in my late teens and early 20's. What a pointless, hazardous activity that is. Good fun though. Sometimes we climbed without ropes. We always abseiled without a safety rope. Stupid eh? One mistake and we were 100% certain of death. Which was, of course, the entire point. I'm a bit too old and responsible for that kind of stuff now but I wouldn't stop others doing the same if they feel the need.
Go for a ride across a field or a campsite in a t-shirt without your lid on and tell me it doesn't feel great.