I think Wiggins may have a point. If there was a sort of social contract, if certain things were expected of cyclists, then cyclists could reasonably expect certain things of society. Let's forget helmets for a moment. Let's imagine that some enquiry said hi-viz clothing and day-time lights would be useful. If that became law, and so was complied with by cyclists, then there would be a reasonable expectation that more should be spent on making the roads safer for cyclists, on making large vehicles easier to drive safely, and that there should be less tolerance of the sort of dangerous driving that kills cyclists and pedestrians.
The idea, from years back, used to be that bicycles should have a bell and reflectors - two things my bikes lack; probably most people's do. But that was the contract back then. Perhaps it needs renewing. I would hope that a new contract wouldn't include the wearing of helmets, but if it did, and if there was a matching resolve to make the changes in our roads and driving laws that would make cycling safer, then I would be prepared to wear a helmet, just to keep my side of the bargain.
I think that's what the mighty Bradley said. He has to wear a helmet because they've been adopted by the Tour de France and other road races. I reckon I could put up with it if it shifted public opinion and policy.